RULES FOR
CLASSIFICATION OF
SHIPS
NEWBUILDINGS
SPECIAL SERVICE AND TYPE
ADDITIONAL CLASS
PART 5 CHAPTER 10
SHIPS FOR CARRIAGE OF
REFRIGERATED CARGOES
JANUARY 1999
SECTIONS
1
2
3
4
5
6
PAGE
General Requirements . . .. .. .. .. .. . . . .. . .. .. .. . . .. .. .. . . . .. .. .. . . .. . .. .. .. .. .. .. .. .. .. .. . .. . .. . . . . .. .. . . .. .. .. . 1
Materials .. .. .. .. .. .. .. .. .. .. .. .. . . . .. . .. .. .. . . .. .. .. . . . .. . .. . . . .. . .. .. .. .. .. .. .. . . .. .. .. . . .. .. .. .. .. . . . .. . .. . . . .. 3
Refrigerating Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Refrigerated Chambers. Construction, Insulation and Instrumentation ............................ 12
Controlled Atmosphere ....................................................................................... 16
Tests .............................................................................................................. 21
DET NORSKE VERITAS
Veritasveien I, N-1322 Hovik, Norway Tel.: +47 67 57 99 00 Fax: +47 67 57 99 11
CHANGES IN THE RULES
General
The present edition of the Rules includes additions and amendments
decided by the Board in December 1998 and supersedes the January
1996 edition of the same chapter. The Rule changes come into force
on !st of July 1999.
Main changes
• General
"Pressure/vacuum" or "PN" have been replaced by "pressure
··
relief' throughout the text.
• Sec.5 Controlled Atmosphere.
This chapter is valid until superseded by a revised chapter. Supplements will not be issued except for an updated list of minor
amendments and corrections presented in Pt.O Ch.I Sec.3. The introduction booklet is normally revised in January and July each
year.
Revised chapters will be forwarded to all subscribers to the Rules.
Buyers of reprints are advised to check the updated list of Rule
chapters printed in Pt.O Ch.1 Sec. I to ensure that the chapter is
current.
B103: Maximum design overpressure is increased to 0,01 bar
(100-mm water column).
ClOl, C102 and F207 text has been amended to reflect more
accurately o 2 and C02 tolerance levels.
GlOl: An item including signboards in the instruction manual
has been added.
Corrections and Clarifications
In addition to the above stated rule amendments, some detected errors have been corrected, and some clarifications have been made
in the existing rule wording.
Connnents to the Rules may be sent by e-mail to dtp203@dnv.com.
For subscription orders or information about subscription terms, pleas_e use distribution@dnv.com.
Comprehensive information about DNV and the Society's services is fOund at the Web site http://www.dnv.com
© Det Norske Veritas AS
Computer Typesetting by Division Technology and Products, Det Norske Veritas AS
Printed in Norway by Det Norske Veritas AS January 1999
l.99.5500
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0
the maximum compensation shall never exceed USO 2 million.
In this provision "Det Norske Veritas" shall inean the Foundation Det Norske Verites es well as ell its subsidiaries, directors, officers, employees, agents and any other acting on behalf
of Oet Norske Verites.
CONTENTS
SEC. 1
GENERAL REQUIREMENTS ....... ...•.. ..••.. ... 1
A. Classification . .• . . •. . . . . .. . . . . .. .. . . •• •. . . .• .. . . .. .. . . •.• •• . . . . .. . . 1
A 100 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A 200 Class notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 1
B. Operational Performance ...................................... 1
B 100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
C. Documentation . . . . . . . . . •• . . . . .. . . . . .. . . . . . . . •. . •• . . . . . .. .. . . . . •• . . 1
C 100 Plans and particulars . . .
.. .. .... .. .... .. .... .. .. . 1
SEC. 2
A.
A
A
A
MATERIALS ....•....•...................••............. 3
Hull Structures •• •. . . •. . . . . . . . . . . .• •. . . . . .. . . . . . . . . . . •. •. . . . .. . . . .
100 Definitions . . . . . . . .. . . . . . . .
. . . . . . .. . . . .. . .
200 Properties . . . . . . . . . . . .
.... .. .... .. ..
300 Allowable stresses . .. . . . . .. . . . . . . . . . . . . . . .. . .
3
3
3
C. Refrigerated Chambers ........ ...... ...... ..••.. ..••.. ... ...... 4
C 100 Insulation . . . . . . . . . . . . . . . . . . .. . . . .
.. . . . . . . . . . . . . . 4
REFRIGERATING PLANT ......................... 5
A.
A
A
A
Design Criteria •• •. .. •. . . . . .. . . . . •. .. .. •. . . . . . . . . . . . .. . •. . . . .. . . . .
100 General . __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
200 Redundancy requirements . . . . . . . . . . . . . . . . . . . .. . . . . .
300 Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A 400
Refrigerants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A 500 Design pressures . . . . . . . . . . . . . . .. . . . . .
.. .. ..... ..
S
5
5
5
6
6
B. Machinery •.................••................••...................
B 100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B 200 Machinery in refrigerated chambers and
cooling/freezing tunnels
... .. .... .. ... ... ..
B 300 Refrigerant circuit
. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .
B 400 Cooling water arrangement. Condenser and brine
cooler capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B 500 Refrigerated seawater tanks (RSW) . . . . . . . . . . . . . . . . .
Compressors . . . . . .
. . . . . .. . . . . .. . . . . .
B 600
. .. . . . . .. . . . . . . .
B 700 Vacuum operation . . . . . . . . . . . . . .. . . . . .
6
6
7
8
8
8
8
8
C. Electrical Installations ..... ..••.. ..••.. ...... .. ...... ...•.. ..••• 9
C 100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
D.
D
D
D
D
D
D
Accessories .... .. ..•. ..••.. .. .... ...... .. ..•••.. ..••.. ...... ...... ..
100 Pipes and tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
200 Pressure vessels and heat exchangers . . .. . . . . .. .
300 Brine piping system and vessels . . . . . . . . . . . . . . . .. . . . . .
400 Safety valves and discharge system . . . . . . .. . . . . .
500 Oil separators, filters and driers . . . .... .. .. .. .. .. .. ..
600 Temperature:, pressure and level indication
9
9
9
9
9
10
10
E.
E
E
E
Instrumentation and Automation ... .•••..•.•... ...... ......
100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
200 Automatic control . . . . .. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .
300 Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
10
10
10
SEC. 4
REFRIGERATED CHAMBERS. CONSTRUCTION, INSULATION AND INSTRUMENTATION ; .•............•....••....••.............. 12
A. Arrangement and Design . . . . . .. . . . . .. . . .. •• . . . . •• . . . . .. . . . . . . 12
A 100 General . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . 12
A 200 RSW tanks . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
B.
B
B
B
B
B
Insulation Construction .. ............. ...... ..••.. ...... ......
100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
200 Insulation on sides, bulkheads and below deck .. . ..
300 Insulation on tank top and ,.tween decks . . . .
400 Insulated hatches and doors . . . . . . . . . . . . . .
500 Protection of cooling grids and refrigerant pipes.
Pipe and other penetrations . . . . . . . .
.... .. ... ... ..
B 600 Lining and protection of insulation . . . . . . . . . . . . . . . .
2
D. Air Circulation System and Dr'ainage, Air, Sounding
and Water Pipes ...••.........•.•..•.•••~ .......................
D 100 Air circulation system . .. . .. .. .. .. . .. . .. .. .. .. .. ..
D 200 Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D 300 Air, sounding and water pipes . .. .. .... .. .. ..
E. Equipment for Temperature Measurements. Gas
13
13
14
14
Indi~
cation Equipment ...... .. ........ ........ .. ..••.. .. ...... .. .....
E 100 Equipment for temperature measurements . ... .... .. .
E 200 C02 indication equipment . . . . . . . .
E 300 Oxygene indication equipment . . . . . . . . . . . . . . .
14
14
15
15
3
B. Refrigerating Plant ... .....•..••.•.. ...... ...... ..••.. ....... .... 3
B 100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 3
SEC. 3
C. Protection against Moisture .................................. 13
C 100 Design and workmanship .. .. .. .. .. .. .. .. .. .. ..
13
12
12
12
13
13
13
13
SEC. 5
CONTROLLED ATMOSPHERE .......•·.......... 16
A.
A
A
A
A
General . . . . . . . . . . . . . . . . . •• . . . . . . .. . . . . . . . . .. . . . . . . . .. . . . . . . •• . . . . ..
100 Application ... ..
... . .. .. .. . . .. .. .. .. .. .. .. .. .
200 Class notations . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
300 Basic assumptions .. ..
... .. .. .. .. .. . .. .. .. .. ...
400 Documentation
. . . .. . . . . . . .. . . . . . . .. . . . . . .. . . . . . . .
16
16
16
16
16
B.
B
B
B
B
B
Arrangement and System ...... .. ........ ..•.••.. .. ...... .. ...
100 General . .. .. . . . .. .. .. .. .. .. . . . . .. .. .. .. .. . .. . . .. .. .. ..
200 Access . . . . . . . . .
. .... .. .. ..... .. .. ...
300 Piping systems . . . . . . . . .. . . . . . . .. . . . . . . . .. . . . . . . . . . . . . . . .
400 Ventilation of adjacent spaces
500 N 2 release prealarm . . . . .. . . . . . . .. . .
17
17
17
17
18
18
C. Operational Performance •.•... .. ...... .. ...... .. .. ..•. .. .. ... 18
C 100 Atmosphere quality .. ... ..
18
C 200 Required capacities .. . .. .. . . .. .. .. . .. .. .. .. .. .. .. .. . . .. . 18
D. Nitrogen Generator. Carbon Dioxide Scrubbers ........ 18
D 100 Nitrogen generator .. ..
.. .. .. .. .. .
18
D 200 Carbon dioxide scrubbers ... .. ... . .. .. . .. .. .. .. .. .. .. . 19
E. Electrical Installations . ... ...... .. .. ...... ........ .. .... .. .. ... 19
E 100 General . .. ..
19
E 200 Cable penetrations
. ... .. . . .. . 19
F.
F
F
F
F
Instrumentation .....•....••........•...............•.•••........
100 General . . . . . . .
.... .. .. ... ... ..
. . . . . . . . . . . . .. . . . .
200 Gas monitoring . . . . .. . . . . . . .
.. . . . . . . . . . .
300 Control of cargo chamber atmosphere . ... .. .. .. .
400 Alarm and monitoring . . . . . . .. . . . . . . . . .. . . . . . . . . . . . . .. .
19
19
19
19
19
G. Instruction Manual. Personnel Protection Equipment 19
G 100 Instruction manual ................. .
19
. .. 20
G 200 Personnel protection equipment ......... .
SEC. 6
TESTS .. ....... .. ...... .. ...... .. ..•.••••.. ...••. .. ....... 21
A. Pressure Tests of Components .. .......... ...... .. ...•.. .. .•. 21
A 100 General . . . . . . . .
. . . . . . . . . . . . . . . . . . 21
A 200 Test pressures . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 21
B.
B
B
B
Pressure Tests after Assembly ..••.•.. ..•.•... .. ...... .......
100 General ...................................................
200 Pressure tests after erection on board . . . . . . . . . . . . . . . .
300 Drying of the refrigerating plant .....................
21
21
21
21
C. Function and Capacity Testing of the Completed Installation ......... ..•..•.. ..••••.. .......... .. ......... ...... .. .... 21
C 100 General ................................................... 21
C 200 Refrigerating machinery, operational test . . . . . . . . . . . 21
C 300 Thennometers. Gas indicating equipment . . . . . . . . . . 22
C 400 Air circulation and air renewal systems . . . . . . . . . . .. . 22
C 500 Chamber tightness test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . · 22
C 600 Insulation and heat balance test . . . . . . . . . . . . . . . . . . . . . . . . 22
C 700 Verification of refrigerating capacity ................. 23
D. Testing of CA installations .................... ...•.•..••••... 23
D 100 General . . . . . . .
.... .. .. ... .... .. ...
23
D 200 Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.1 - Page 1
SECTION 1
GENERAL REQUIREMENTS
Contents
given the class notation RM (. .. ° Cl ... ° C sea) (lowest
chamber temperature/maximum seawater temperature).
A. Classification
A 100
A 200
204 Ships intended for transport of refrigerated containers
with cooling provided by the ship's refrigerating plant may
be given the class notation RM Container.
Application
Class notations
B. Operational Performance
B 100
205 Ships built and fully equipped for carriage of bananas
and fruit in general under a controlled cargo chamber atmosphere in at least 50% of the ship's total refrigerated
cargo chamber volume may be given the class notation
CA.
General
C. Documentation
C 100
Plans and particulars
A. Classification
A 100
Application
101 The Rules, as relevant, in this Chapter apply to ships
with refrigerating plants for
- carriage of refrigerated dry cargo
- carriage of fruit or vegetables under a controlled atmosphere
- cooling down or freezing catches of fish or
- carriage in bulk of refrigerated fruit juices and similar liquid cargoes
206 Ships built and equipped for carriage of bananas and
fruit in general under a controlled cargo chamber atmosphere in at least 50% of the ship's total refrigerated cargo
chamber volume except that a nitrogen generating unit and
possibly parts of the alarm and monitoring equipment have
not been permanently installed may be given the class notation CA (port.).
207 Ships built for bulk transport of fruit juices and similar
cargoes in refrigerated tanks may be given the class notation
Refrigerated Fruit Juice Carrier provided they also comply with relevant parts of the rules in Ch.4.
B. Operational Performance
when a class notation in 200 is requested.
102 The safety and environmental requirements of this
Chapter, as identified by being printed in bold italics apply
to all ships as specified in Pt.4 Ch.I Sec.3 AllOI to A1103
except as follows:
For fixed refrigerating plants with a total prime mover rated
effect of less than 56 kW and with a design evaporating
temperature not colder than -41 'C,
- Sec.2 B (refrigerating plant material requirements); need
not be applied
- Sec.3 B103 (breathing apparatuses); need not be applied
- Sec.3 B106 to Bl 12, Sec.3 B114 to B116 (refrigerating
machinery requirements for Group 2 refrigerants including R717); will be specially considered
- Sec. 3 D 10 I to D 103, D 105 (refrigerant pipes and tubes
materials requirements); need not be applied
- Sec.3 D204 to D207 (heat exchangers); need not be applied
- Sec.3 E302 (refrigerant leakage detection); need not be
applied for Group I refrigerants and will be specially
considered for Group 2 refrigerants
- survey during construction, installation and testing of the
plant is not required at makers facilities or onboard the
ship.
A 200
Class notations
201 Ships designed, built, equipped and tested under the
supervision of the Society in compliance with the requirements of this Chapter may be given one of the additional
class notations in 202 to 207.
202 Ships built mainly for carriage of refrigerated dry
cargo may be given the class notation Reefer (. .. °C/ ... °C
sea) (lowest chamber temperature/maximum seawater temperature).
203 Dry cargo ships having a partial cargo carrying capacity for refrigerated cargo or fishing vessels with refrigerating plant for cooling or freezing catches of fish, may be
B 100
General
101 The ship is to be designed, arranged and equipped to
make it suitable for cooling down and/or carrying cargoes,
freezing catches of fish etc. as relevant according to the design operating conditions specified by the Builders and subsequently to be stated in the Appendix to the Classification
Certificate. The Builders' and possible subcontractors' specifications of the ship's operational performances and abilities will together with the specific requirements of this
Chapter be used as basis for assignment of Class.
C. Documentation
C 100
Plans and particulars
101 The following plans and particulars are to be submitted for approval:
an arrangement plan of the insulated chambers with
cross-sectional and plan views showing:
- the position of the chambers in the ship
- the purpose of adjacent rooms
- adjacent bunker tanks with indications of their maximum temperature
- the dimensions and spacing of frames, girders, and
other details which project into the insulation or the
chambers
- pipes, ducts etc. which lead through the chambers
- a plan showing access and escape arrangements for
chambers and air cooler rooms
- insulation drawings for chambers and brine rooms including:
- a list specifying the insulation materials to be used
(samples may also be required) and application and
production procedures when applicable
- insulation with thicknesses and details of fastening
- internal lining of the chambers and brine rooms
- suspension and fastening of refrigeration pipes etc.
-
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 2 - Pt.5 Ch. 10 Sec. 1
-
passages for the refrigeration pipes through the bulkheads and decks
- insulation of doors, hatches, cargo ports, etc.
arrangement plans of air cooler rooms, air ducts and air
distribution systems within the chambers, air coolers, and
fans with specifications of the dimensions and cross-sectional area of the ducts
specifications of the paint system or other corrosion protection of structural steel and pipes
piping and instrumentation diagrams for refrigerant and
auxiliary systems
RSW piping diagram
specification of the defrosting procedure
a plan showing the position of the sensors for remote and
local thermometers, C02 sensors and refrigerant leakage
detection sensors
specifications and drawings of detection equipment for
temperature, C02 and refrigerant leakage
a plan showing the position of the drain, air and sounding
pipes and thermometer tubes with their protection and
insulation
cargo chamber bilge and drain arrangement. Liquidsealed traps and check valves
an arrangement plan of the refrigerating machinery room
with specifications of the ventilation system
a cross-sectional plan of the compressors
a plan of the crankshaft of the compressors
a plan of the condensers, brine and rsw coolers, air
coolers, oil separators, liquid receivers and other pressure ships
a plan of the plate freezers and tunnels
an arrangement plan of process areas etc. where R717
freezing/cooling equipment is located showing also accesses,. emergency escapes and ventilation system
electrical wiring diagram for the refrigeration installation
a progran1 for function, insulation and capacity testing
after completion
-
-
-
a calculation procedure, based on data recorded during
the balance test, to verify the refrigeration capacities at
all design operating conditions.
Documentation requirements for insulation and lining of
RSW tanks are covered by Ch.6.
-
102 The following particulars are to be submitted for information:
- detailed specification of the refrigerating installation. All
design operating conditions and all operational performances and abilities of the installation are to be given
- the operation manual for the refrigeration installation
- the specified overall heat transfer coefficient of the insulation, (with the areas to be used for this purpose)
- calculation of the refrigeration loads at all design operating conditions
- capacity curves/capacity data for the compressors, fans,
pumps, condensers, brine and RSW coolers and air
coolers
- calculations, based on data recorded during the balance
test, to verify sufficient refrigeration capacity at all design operating conditions.
103 For general requirements for documentation of instrumentation and automation, including computer based
control and monitoring, see Pt.4 Ch.5 Sec.!.
104 For the instrumentation systems listed, documentation
is to be submitted according to Table C 1. The upper row
of Table C 1 refers to the documentation types defined in
Pt.4 Ch.5 Sec. I CZOO.
105
For ships without class notations according to this Chapter
(see Pt.4 Ch.I Sec.3 AllOI and All03), and with fixed refrigerating plants with a total prime mover rated effect of 56 kW and
above or with controlled atmosphere instatlations, documentation
covering the applicable safety requirements are to be submitted.
106 Documentation required for class notations CA and
CA (port.) is given in Sec.5 A400.
Table Cl Requirements for documentation of instrumentation systems
020 030 040 050 060 070 080 090 100 llO 115
For all class notations defined in A200:
CCM
CHO
C02
x
x
x
x
x
x
x
x
x
REP
In addition for class notation CA:
021
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Instrumentation systems:
Cargo cooling system control and monitoring
CCM
CHO
C02
021
Carbon dioxide indication equipment
Oxygen indication equipment
REP
Refrigerant leakage detection system
Cargo hold temperature control and monitoring system
x
x
130
140
150
x
x
x
x
x
x
160
170
180
190
200
x
Documentation types:
Functional description
030
040
050
070
080
!IJO
110
120
140
150
T
120
System block diagrams (T)
System diagrams (P&!Ds, D&!Ds, etc.) (T)
Power supply arrangement (T)
Arrangement and layout (T)
Instrument and equipment list (T)
Data sheets with environmental specifications
Description of functions covered by software
Test program for application software at manufacturer (T)
Test program for quay/sea trial (T)
Required also for type approved systems
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch. 10 Sec.2 - Page 3
SECTION2
MATERIALS
Contents
f2
A. Hull Structures
A 100
A 200
A 300
Zn
Definitions
Properties
Allowable stresses
z,
B, Refrigerating Plant
B JOO General
a1
C. Refrigerated Chambers
C 100
Insulation
= stress factor as defrned in Pt.3 Ch.I.
= vertical distance in m from the baseline or deckline to the
neutral axis of the hull girder, whichever is relevant.
= vertical distance in m from the baseline or deck/ine to the
point in question below or above the neutral axis, respectively,
In the deck plate at a hatch corner the longitudinal stress
"'is to be multiplied by 2.
= thermal stress.
"b
t,
)
N/mm2
30
= local bending stress (tensile) in girders in Nlmm 2,
= 50 ( _
A. Hull Structures
A 200 Properties
201 The properties of steel materials in hull structural members
A 100 Definitions
101 Symbols:
ts
atv
"•
= steel temperature, defmed as the temperature of the material when the refrigerated chamber is at its lowest service
temperature and the ambient temperature is 0°C. Where
structures protrude into refrigerated spaces (e.g. rounded
deck plates at hatch corners, deep girders etc.) and are
insulated· on both sides, the temperature tfii... in such structures is not to be taken higher than 10°L above the refrigerated chamber temperature.
The temperature ~--in web plates may be taken as the average of the two 1mnges.
= tensile stress in transverse girder flanges.
= ai+ah
= total longitudinal tensile stress in plating or girders.
=az+ai+ab
al
=
A 300 Allowable stresses
301
The local tensile stress at+ ah in transverse and longitudinal girders is not to exceed 190 f 1 N!mm2.
302
N!mm 2.
longitudinal tensile stress in hull girder.
= 135 f2
at temperatures ts below -5°C are to be as given in Table Al.
The requirements are based on the assumption that structural details are carefully designed. Also in 'tween decks the hatch
openings and smaller openings are to have well rounded corners.
For steel structures completely on the chamber side of the insulation ts may normally be taken as the chamber temperature.
For structure outside of the insukltion, material grades may normally be selected according to Pt.3 Ch.I.
Zn- Za
Zn
"'
=
The total longitudinal stress "" is not to exceed 225 ti
_J.,2 + 3,2
is not to exceed 235 f 1 N/mm2.
Table Al Hull materials for refrigerated cargo vessels with t, 2: -40°C (Structural elements with t, < -40°C to be specially
considered
Required mini'mum grade of steel.
Structural members
CTzt or crf'
Nlmm
Plating and longitudinal girders in
NVE for -30°C s ~ s -I0°C. NVD for~> -10°C. 1l
> 160?,
strength deck (upper continuous
NVE fort, S -20° . NVD fort, > -20° . 1)
s
160
1
deck).
NVE fort. s -20°C. NVD fort. > -20°C.
> 160f,
Plating and longitudinal girders in
NVE in plating and longitudinal girders along hatches (including deck plating
at hatch corners and above pilklrs) for an area extending transversely not less
decks below strength deck.
I00-160ti
Flanges of stringers at ships sides.
than 1,5 metres outside hatches, when t, < - 20°C. NVD when t, 2: -20°C,
Flanges of transverse girders in
NVD elsewhere.
strength and tween decks and at
NVD in plating and longitudinal girders along hatches (including deck plating
sides. Girder flanges in hatch
at hatch corners and above pilklrs) for an area extending transversely not less
covers.
< 100 ti
than 1,5 metres outside hatches, when t, < - 20°C. NVB when t, 2: -20°C,
NVB elsewhere,
NVD when t, S - 20°C and thickness t 2: lOmm.
Web plates in transverse girders in decks and at
sides, stringers at sides and girders in hfch covers, NVB when t, > - 20°C,
where shear stress exceeds 60 ti N!mm .
NVB when t, S - 20°C and thickness t < lOmm.
I) Fort,< -30°C minimum impact energy 271 at a temperature I0°C below t,.
For a closed refrigerating circuit using refrigerants of Group 1
or R717 and with a lowest design evaporating temperature of
-41°C or warmer:
B. Refrigerating Plaut
B 100 General
101
The materials are generally to comply with the requirements specified in Pt.2, Pt.4 Ch.I Sec.2 and Pt.4 Ch.3 Sec.2,
Other suitable material specifications will be considered for approval in each individual case. The materials are to be tested in
accordance with the regukltions for material testing given in Pt.2.
- rolled steel plates will be accepted in accordance with Pt.2 Ch.2
Sec.2 B. A grade impact tested at 0°C (or colder) is to be selected
- steel pipes and filtings will be accepted in accordance with Pt.2
Ch.2 Sec.4 B.
In such systems for lower design evaporating temperatures and
for other Group 2 refrigerants rolled steel plates and steel pipes
and futings are to comply with Ch.5.
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 4 - Pt.5 Ch. 10 Sec.2
Possible sub-cooling of the liquUJ in connection with accUJental
blow down need not be taken into account when decUJing the design temperature.
For refrigerating systems on gas carriers where the cargo is used
as refrigerant the materials and the design temperature are to be
in accordance with Ch.5.
102 The materials are to be corrosion-resistant to the refrigerant and the compressor oil and to the combination of the two.
103 The following materials and refrigerants are not to be
combined:
1) Copper with ammonia.
2) Magnesium with fluorinated hydrocarbons.
3) Zinc with ammonia and fluorinated hydrocarbons.
C. Refrigerated Chambers
C 100 Insulatiou
101 The insulation material is to have the following qualities:
- it is not to absorb and give off odours or gases which
may affect the cargo
- it is to have good mechanical resistance to vibrations and
deformations at the actual temp~ratures. Disintegration
and structural changes are not to occur
- it is to be resistant to decay and be chemically neutral
- it is to have high insulating properties. When insulation
materials with low resistance against moisture transmission and air movements are used, the integrity and
completeness of the lining and vapour barrier is to be
given special attention.
102 The insulation material is to be durable at working
temperatures and temperature variations. Material placed on
surfaces which may be exposed to direct sunshine, on tanks
which are heated, etc. is to withstand at least 100°C.without
being destroyed. Use of wood will be specially considered.
103 Organic foams are to be of a flame-retarding quality, i.e.
low ignitability and low flume-spread properties. Testing is to be
carried out in accordance with a recognized standard, e.g. DIN
4102 IB2, or equivalent. The test method chosen is to be suitable
for the type of foam in question.
104 A foam •in-situ» type of insulation may be used when
full details of the process have been approved.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch. 10 Sec.3 - Page 5
SECTION 3
REFRIGERATING PLANT
Contents
A.
A
A
A
A
A
- other specified operating conditions.
The design operating conditions will be specified in the Appendix to Classification Certificate.
Design Criteria
100
200
300
400
500
General
Redundancy requirements
Capacity
Refrigerants
Design pressures
103 Wherever this Chapter includes requirements to brine
systems/components these requirements are, as far as relevant also applicable in case of other secondary systems e.g.
systems using glycol/water mixtures.
B. Machinery
B 100 General
B 200 Machinery in refrigerated chambers and cooling/freezing
tunnels
B 300 Refrigerant circuit
B 400 Cooling water arrangement. Condenser and brine cooler
capacity
B 500 Refrigerated seawater tanks (RSW)
B 600 Compressors
B 700 Vacuum operation
C. Electrical Installations
C 100
D.
D
D
D
D
D
D
For ships with class notation RM at least two complete
refrigeration compressors with drive motors are to be fitted.
203
In the case of separate refrigeration plants fitted for
individual chambers or groups of chambers, the question of
standby units required will be subject to special consideration.
204 With indirect cooling and with circulation of the refrigerant by pumps, a standby pump, arranged for immediate use, is to be installed. The capacity of the standby pump
is not to be less than that of the largest of the other pumps,
and it is not to be arranged for other purposes on board.
E. Instrumentation and Automation
E 100 General
Automatic control
Monitoring
205 When two or more refrigeration units, refrigeration
compressors, cooling water pumps, brine pumps, etc. are
required for redundancy purposes these are to have separate
electrical supply.
A. Design Criteria
A 100 General
101 The refrigerating plant with machinery and all components and accessories is in every respect to function satisfactorily at the following conditions:
- permanent list: 15 °
- rolling: ± 22,5'
- trim and pitch according to Table Al.
Trim and pitch
Aft
Fotward
Pitch l) )
<100
5'
2'
±10
0
Length of ship in m
5'300
<200
2,5°
1,5°
1'
0,5°
±7,5 °
A 300 Capacity
301 With any one of the units or compressors required by
201, alternatively 202 being out of operation, the available
capacity is to be sufficient to maintain the chamber temperature 'at all design operating conditions. In case of forced air
circulation, the chamber temperature is defined as:
- delivery air· temperature in the case of temperatures above
O'C
- return air temperature in the case of temperatures below
O'C.
Table AI Trim and pitch
Trim l)
complete refrigeration units are to be fitted. Each unit is at
least to consist of compressor with drive motor and lubricating oil pump if fitted, condenser, brine cooler, if relevant,
and necessary piping and valves for running the units independently of each other.
The arrangement is to be such that each unit may be connected to any one chamber.
202
General
Accessories
100 Pipes and tubes
200 Pressure vessels and heat exchangers
300 Brine piping system and vessels
400 Safety valves and discharge system
500 Oil separators, filters and driers
600 Temperature, pressure and level indication
E 200
E 300
A 200 Redundancy requirements
201 For ships with class notation Reefer at least two
±5
0
>300
302 The maximum seawater temperature for which the
I'
plant is designed is as specified in the class notation. The
average outside air temperature for a 24-hour period is to
be taken as 3'C above the specified seawater temperature.
The air humidity is assumed to be 70 %.
0,3°
±3
0
I) Other values may be accepted if justified by calculations for the actual ship.
2) From even keel or designed rake of keel.
102 The refrigerating plant is to be designed for one or
more of the following operating conditions:
- carriage of frozen cargo at -20'C or colder
- freezing down from ambient to -20 °C or colder a specified quantity of fish or fish products per 24 hours
- carriage of fruit in general at approximately +4 'C to O'C
- carriage of bananas at approximately +12'C
Guidance note:
Typical values for maximum seawater temperatures:
Tropical waters, open sea
Tropical coastal waters
30°C
32'C
The Persian Gulf
35'C
The Mediterranean
27'C
The North Sea
20'C
DET NORSKE VERITAS
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Rules for Ships , January 1999
Page 6 - Pt.5 Ch. 1O Sec.3
303 For fruit in general and bananas the total capacity of
the refrigeration plants is to be sufficient to lower the temperature of the entire cargo from the average day temperature of the loading port to the specified transporting
temperature within a reasonable period of time.
Guidance note:
The capacity requirement of 303 is considered to be complied
with if an excess capacity of minimum 33% relative to that required to maintain the cargo at specified chamber temperatures
during the carriage is available, i.e. with 4 equal units fitted, 3
must fulfil the capacity requirement in 301.
102 If the refrigerating plant is located in a separate room
outside the machinery space, this room is to be equipped
with effective ventilation for cooling_ the refrigerating machinery. The mechanical ventilation is to have two main
controls, one of which is to be operable from a place outside
··
the room.
103 At least two sets of air breathing apparatuses with spare
air bottles are to be available onboard. The breathing apparatuses
may be the same as those required for other purposes, e.g. SOLAS, provilled the ship is equipped with an air compressor for
recharging the air bottles.
104 A complete operation manual for the refrigeration installation is to be available onboard.
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A 400 Refrigerants
105
401 Group 1:
Refrigerants in this group are normally nonpoisonous, but all of
them can be poisonous when decomposed by a flame or by a hot
106 Refrigerant gas masks and hermetically sealed ftlters are
to be available in a glass door case located immediately outsille
each entrance to the space where the refrigerating machinery is
located. Additionally at least two sets of suitable protective clothing including also gloves and boots are to be available onboard
and located in the vicinity of the space for the refrigerating machinery. In case any one refrigerant circuit contains more than
25 kg refrigerant the two sets of protective clothing are to be gas
tight suits with permanently attached boots and gloves and suitable
for use in combination with the air breathing apparatuses.
surface. These refrigerants are heavier than air, give no odour
warning and will give a dangerous atmosphere by disp/a.cement
of air. The lack of odour and the high density make these refrigerants particularly dangerous with regard to suffocation.
R22 (monochlorodifluoromethane)
R!34a (1, I, 1,2-tetratluoroethan)
CHF Cl
CH F-CF
402
Group 2:
Refrigerants in this group are particularly poisonous. R717 is
lighter than air and is flammable in very high mixing ratios with
air. A very high ignition energy is then required to start a fue.
IR717 (ammonia)
403 Chlorofluorocarbons (CFCs) whose ozone depleting potential is higher than 5% of Rll is not to be used. (Ihis requirement
applies to all frxed refrigeration installations regardless of size,
see. Pt.4 Ch.I Sec.3 Al102.).
404 The use of other refrigerants will be given special consiJJeration.
A 500 Design pressures
501
The scantlings of the various parts of the refrigerating
plant are to be based on the pressures specifwd in Table A2.
Table A2 Design pressures for refrigerating plant
Refrigerant
R22
Rl34a
R717
Minimum design pressure bar
HP side
LP side
of system
of system
22
14
22
I5
11
I5
502
If refrigerants other than those specified in Table A2 are
used, the design pressure is subject to approval in each individual
case. It may, in general, be assumed to be equal to the vapour
saturation pressure of the refrigerant at 55°C and 45°C on the
HP and LP silles, respectively.
107 Except as permitted in 115 and 116, the complete refrigerant circuit is to be located within a separate machinery room
surrounded by steel decks and bulkheads and fitted with selfclosing doors opening outwards and with a sill height of at least
300 mm but not less than sufftcient to prevent overflow of refrigerant in case 80% of the total refrigerant quantity of the largest
unit is released while the ship is within normal range of trim and
with a list not exceeding I5°. Decks and bulkheads are to be
without openings and pipe and cable penetrations etc. are to be
sufficiently tight to prevent leaked refrigerant from entering other
rooms and spaces. Special gklnds of approved type need, however, not be used.
The refrigerating machinery room is to be located as high as
reasonable within the ship. The refrigerating machinery room is
subject to approval with regard to its location and arrangement
within the ship and with regard to accesses and emergency escapes. Except for small refrigerating machinery rooms, at least
two access doors are to be provided.
108 Thin-plate ventilation ducts for other spaces are not to be
lead through the refrigerating machinery room. Air coolers for
air conditioning plants are not to be located within the refrigerating machinery room.
109 The ventilation system for the refrigerating machinery room
is to be separated from other ventilation systems, is to be of the
exhaust type and to give minimum 30 air changes per hour. If the
refrigerant is lighter than air the ventilation exhaust is to be from
the top of the refrigerating machinery room.
110
The refrigerating machinery room is additionally to be
equipped with effective mechanical catastrophe ventilation. For
R717 the capacity is to be the larger of the vallles calculated by:
- 7,2 m 3 /h for each kg refrigerant up to 500 kg pills 3,0 m3!h
for each kg refrigerant above 500 kg. In case the refrigerant
is contained in completel;y separated refrigerant circuits, only
the circuit with the largest quantity need be consillered; or
- 300 m 3!hfor each ,;,2 deck area of the refrigerating machinery
room. Special considerations will be made in case the deck is
thermally insulated to reduce evaporation of leaked refrigerant
or the wet area is minimised by the deck shape or construction.
For other refrigerants the required capacity is to be corrected according to the evaporating heat of the refrigerant at atmospheric
,pressure and the acceptable concentration in the ventilation exhaust air.
B. Machinery
B 100
Items 106 to 116 apply to refrigerants of Gro\Jp 2.
General
101 All parts of the machinery are to be easily accessible
for inspection and overhauling. Sufficient space for cleaning
and replacing the tubes in the brine and RSW coolers and
condensers is to be available.
111 All ventilation outlets from the refrigerating machinery
room are to be at safe locations with regard to:
- the hawrds of possibly leaked refrigerant in the ventilation air
- intake of ventilation air into other ventilation systems on the
ship
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.3 - Page 7
- recycling between the ventilation outlets and intakes for the
refrigerating machinery room.
112 When the arrangement is such that a combined ventilation
failure/refrigerant leakage within the refrigerating machinery
room is considered hazardous for the continued operation and
safety of the ship, the normal and the catastrophe ventilation are
to be arranged such that a single failure cannot cause a complete
ventilation failure for the refrigerating machinery room.
113 The normal and the catastrophe ventilation are to be
arranged such that a single failure cannot cause a complete
ventilation failure for the refrigerating machinery room.
114 If R717 is used as refrigerant the required separate refrigerating machinery room is to comply with the following:
- bilge wells and other recesses where leakage water will accumulate are not to be arranged
- the deck plating is to be arranged for easy cleaning and drying.
Separate floor plating above the deck plating of the refrigerating machinery room is not to be filled
- drain piping to bilge systems/bilge wells/bilges in other parts
of the ship are not be arranged unless they are jilted with self
closing valves
- all non-Ex protected electrical equipment within the refrigerating machinery room is to be automatically de-energised in case
an R717 concentration above 1000 PPM is detected. Jn case
112 or 113 apply the normal and catastrophe ventilation systems are to be arranged with Ex protected motors and nonsparking fans
- ex protected (emergency) lighting futures are to be jilted in the
refrigerating machinery room
- access doors and emergency escapes are to be arranged as air
locks fitted with emergency showers, eye washes and water
screens with constantly available water supply. Drainage from
the air locks may be to bilges/bilge wells in other spaces provided adequate water seal is arranged.
Separate refrigerating machinery rooms for R717 systems with
less than 25 kg filling will be specially considered.
115 R717 may be used for direct expansion in cooling I freezing equipment located outside the refrigerating machinery room
and within nonnally manned spaces such as production areas and
cooled I frozen product cargo chambers on fishing vessels and
fish factory ships. R717 piping is not to be located within the crew
accommodation spaces, the navigating bridge and the main engine
room or such that all accesses to the main engine room will be
blocked in case of pipe rupture. Gas masks as referred to in 106
and emergency showers and eye washes as referred to in 114 are
additionally required to be located outside all normal accesses to
such spaces and cargo chambers. A water hose of adequate
length with fog nozzle and constantly available water supply is to
be located outside the main entrance to any such production area.
For such areas
- their arrangement within the ship with tightness of bulkheads
and decks,
- self closing door arrangement,
- accesses and emergency escapes, and
- ventilation arrangement (of under pressure type)
are subject to special approval.
116 On ships of less than 65 m of length (as def"med in Pt.3
Ch.2 Sec.I BJOJ) R717 refrigerating systems with less than 25
kg filling may be located within the engine room or another suitable space not including accommodation spaces. All parts of such
refrigerating systems are to be located together. A secondary refrigerant or a heat transfer fluid are to be used in the air coolers
in provision stores, air conditioning systems etc. connected to such
refrigerating systems. The area where the refrigerating system is
installed is to be jilted with a hood with a negative ventilation
system and with a water spray system. The outlet from the ventilation system is to be arranged in accordance with 111.
"
B 200 Machinery in refrigerated chambers and
cooling/freezing tunnels
201 For plants with direct expansion the total air cooler
area/cooling grid area in each chamber is normally to be
sufficient to ensure that the evaporating temperature is
maximum 10°C colder than the chamber temperature as
defined in A301 in any of the design operating conditions.
For indirect systems the mean value between the in- and
outgoing brine temperatures are to be used in lieu of the
evaporating temperature. When considering the capacity of
the air coolers, the brine velocity is nowhere to exceed the
values given as guidance in D204.
The air cooler overall heat transfer coefficient measured
during the heat balance test shall be assumed c<mstant whe.n
the verification calculations (based on the balance test results) of the cooling capacity at all design operating conditions are carried out.
202 In each chamber the air coolers are to be divided into
at least two independent units with separate electrical supply
for their air circulation fan(s), so that any one of them may
be shut off without essentially influencing the others. For
small spaces up to 300 m3 one unit may be considered.
203 In chambers fitted with cooling grids at least two independent circuits must be installed, so that any one of them
may be closed without essentially influencing the others. For
small spaces up to 200 m3 one unit may be considered.
204 In case of sub-zero air cooler temperature a defrosting
system is to be installed.
205
Drip trays with water drainage are to be located under
air coolers with forced air circulation and under cooling
grids fitted vertically on bulkheads or ship sides. Drain
pipes shall have an internal diameter of not less than 50 mm.
For ships for frozen cargo the drip trays and drain pipes
shall be fitted with heat tracing or alternative means for
heating where relevant.
206 Fans and air coolers are to be easily accessible.
Change of fan motors and fans is to be possible with the
chambers fully loaded.
207 Where forced air circulation is installed, the fans shall
be arranged with alarm for fan failure.
208 AU air cooler and freezing tunnel fans are to be jilted with
effective protection grids or equivalent.
209 Fan emergency shut down buttons are to be fitted in all air
cooler rooms or similarly.
210 Motors and other electrical equipment are to have suitable
enclosures, see Pt.4 Ch.4 Sec.2 C.
211 For chambers fitted with coolers with forced air circulation, the number of air circulations is to be at least:
- 90 pr. hour for bananas
- 60 pr. hour for fruit in general
- 30 pr. hour for frozen cargo.
Even distribution of the circulated air without
is to be arranged.
.:blind~
zones
Guidance note:
To obtain even distribution of the air, it is essential that the
pressure losses in the distribution ducting/grating are small· both
longitudinally and athwartship compared to the losses at the inlet
"nozzles" to the chamber. This will ensure that the various
"nozzles" are supplied with the same air overpressure. Uncontrolled air supply to the chamber e.g. in connection with 'tween
deck hatches or "leakages" between the grating and bulkheads/
shipsides should be kept as low as possible.
For an air circulation system with the air supply through a
homogeneously perforated grating, the highest mean air velocity
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 8 - Pt.5 Ch.10 Sec.3
through the perforations in any section of the grating should,
when measured in an empty chamber, not exceed the lowest
mean velocity in any other section by more than 75%.
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212 If the ship is to carry cargo in areas where the temperature in the chambers may fall below that specified for
the cargo, it must be possible to heat the refrigerated chambers.
213 Chambers intended for bananas or fruit in general are
to be equipped with an effective ventilation system giving
at least 2 air renewals pr. hour. Each chamber is to have
closeable separate feed and discharge ducts. The air intake
is to be so placed that the possibility of foul air (from ventilation outlets from the same or other cargo chambers or
from other ventilation outlets) coming into the chamber is
reduced to a minimum. The air intake is normally to be
located at least B/4 away from any ventilation outlet.
214 The required air circulation rates in 211 and air renewal rates in 213 are to be based upon the bale chamber
volumes.
215 Other air circulation and air renewal rates than given
in 211 and 213 may be accepted upon request and will then
be specified in the Appendix to Classification Certificate.
B 300
Refrigerant circuit
301 A direct expansion system is to be fitted with shut off
valves to divide the system into a suitable number of sections. A section may include e.g. all chambers below the
same hatch. The shut off valves shall be located outside the
refrigerated chambers and shall be installed to ensure that
the section may be completely separated for maintenance or
repair etc. without affecting the operation of the other sections.
302 Shut off valves are to be fitted upstream and downstream of all filters, strainers and automatic expansion valves
to facilitate cleaning, replacements and repairs.
303
Where R717 is used as refrigerant for direct expansion
within production areas and cargo chambers in accordance with
115, quick closing valves are to be fitted in the delivery lines (liquid and hot gas) within the refrigerating machinery room. The
return lines are likewise within the refrigerating room to be fllled
with a valve arrangement providing a quick closing function for
prevention of flow towards the evaporators and a non7'return
function allowing flow towards the low pressure side within the
refrigerating machinery room. All delivery line quick closing
valves are to have common activation. AU return line quick closing functions are to have common activation, however, separated
from that of the delivery lines. Activation is to be possible from
the refrigerating machinery room, the production area and from
a suitably located emergency station outside these rooms.
304
For fixed refrigerating plants with a total prime mover
rated effect of 56 kW and above using a refrigerant subject to a
«phase-out» schedule under the Montreal Protocol, as amended,
due to an ozane depleting potential of the refrigerant, are to be
provided with arrangements, incb.tding portable equipment as relevant, to facilitate recovery of the refrigerant prior to opening up
the system for maintenance, inspections and repairs. Alternative
storage vessels for the complete refrigerant filling are not required.
B 400 Cooling water arrangement. Condenser and
brine cooler capacity
401 Cooling water is to be supplied from at least two sea
connections to the water-cooled components of the refrigerating plant. For sea connections, see Pt.4 Ch. I Sec.5.
402 A standby cooling-water pump, arranged for immediate use, is to be installed. The capacity of the standby pump
is not to be less than that of the largest of the other pumps.
Automatic start of the standby pump.need not be arranged.
403 The standby pump may also be used for other purposes on board, provided it has sufficient capacity .to serve
the refrigerating machinery at the same time.
404 With clean sea water side and water velocity as given
by the normal sea water pump, however not exceeding the
values given as guidance in D204, the condenser heat
transfer capacity is normally to be sufficient to ensure that
the condensing temperature is maximum 6°C warmer than
the in-going sea water temperature in any of the design operating conditions.
When considering the overall refrigerating capacity, the
condensing temperature shall be increased from the value
found by the heat balance test by 2°C to take into account
the fouling of the sea water side of the condenser.
405 The brine coolers are to be designed to ensure that the
evaporating temperature normally is not more than 6°C
colder than the mean between the in- and outgoing brine
temperatures.
An increased design temperature difference across the brine
coolers, however not exceeding 8°C, will be accepted provided the sum of the design temperature differences across
the brine coolers and the air coolers (see 201) does not exceed 16°C.
B 500
Refrigerated seawater tanks (RSW)
501 Refrigerated seawater tanks for storage of catches of
fish are to be kept at a temperature of - 1°C at design ambient condition. The maximum allowable variation of the
RSW temperature is 2°C. The arrangements of water inlets
and outlets are to be such as to ensure even temperature
distribution throughout the tank.
502 The RSW cooler is to be protected against freezing,
e.g. by automatic shut-off of refrigerant suction line or automatic stop of the compressor(s) at loss of circulation.
503 A standby circulation pump is to be fitted. The
standby pump may also serve other seawater services on
board.
B 600
Compressors
601 Compressors are to comply with the Rules Pt.4 Ch.2
Sec.10. For ships with RM notation, materials for the compressor will be accepted with test report on material properties.
602 The compressors are to be equipped with all the accessories and instruments necessary for effective and dependable operation.
603 Oil coolers are to be installed, unless the service area
of the cargo refrigerating plant is restricted to non-tropical
waters.
604 The low-pressure side of the compressor or the plant is to
be so constructed that liquid refrigerant or oil cannot be sucked
into the compressor in harmful quantities.
605 Safety valves or safety discs are to be located on the highpressure side of the compressor ahead of the shutoff valve. The
outlet may lead back to the suction side of the compressor.
B 700
Vacuum operation
701 A refrigeration plant designed to operate with suction
pressure below atmospheric is to be fitted with air separating
equipment.
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Rules for Ships , January 1999
Pt.5 Ch. 10 Sec.3 - Page 9
Guidance note:
Insulation and water vapour barriers should preferably be led
continuously through the fastening arrangements.
C. Electrical Installations
C 100
General
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101 All electrical installations are to comply with Pt.4 Ch.4.
D 200
D. Accessories
D 100
Pipes and tubes
101 Pipes and systems are to comply with Pt.4 Ch.1 Sec.6 and
Sec. 7 except where otherwise stated in this Chapter. Copper tubes
and systems may be accepted with minimum wall thicknesses in
accordance with Table DJ. Welding of steel pipes is to be carried
out according to an apprQved procedure.
Table Dl Minimum nominal wall thickness for copper tubes
for refrigerating systems
(The table values correspond to ASTM B-280)
Wall thickness, mm
External
Dimension
diameter, mm
annealed
halfhard
1/8
3/16
1/4
5/16
3/8
112
5/8
3/4
7/8
1 1/8
1 3/8
1 5/8
2 1/8
2 5/8
102
3,18
4,75
6,35
7,92
9,52
12,7
15,9
19,1
22,3
28,6
34,9
41,3
54,0
66,7
0,762
0,762
0,762
0,813
0,813
0,813
0,889
0,889
1,14
Pressure vessels and heat exchangers
201 Pressure vessels are to be constructed in accordance with
Pt.4 Ch.3. Pressure vessels for refrigerant of Group 2 are to
comply with the requirements for Chzss I pressure vessels. Requirements for thermal stress relief of pressure vessels with fluids
liable to cause stress corrosion cracking (e.g. ammonia, R717) are
given in Pt.4 Ch.3 Sec.8 CJOJ.
202 Pressure vessels in closed refrigerating circuits will normally be accepted without inspection openings.
203 Receivers with shut off valves which together can take
the complete filling of refrigerant are to be installed.
204 Condenser cooling water tubes are to be made of materials
with high resistance to corrosion and erosion.
Guidance note:
The water velocity should not exceed:
2,5 mis for aluminium brass pipes
2,5 m/s for 90/10 copper/nickel pipes
1,5 mis for steel pipes.
0,762
0,889
1,02
1,07
1,14
1,27
1,40
1,52
1,78
2,03
Flexible hoses are to be of approved type.
103 When R717 is used the complete refrigerant circuit, including both low- and high pressure sides, is to be considered as
pertaining to Class II piping systems.
104 Piping which may be exposed to moisture, is to be
protected against corrosion.
Guidance note:
For mild steel pipes hot dip galvanizing (min. 70 microns) or
shot blasting to SA 2.5 followed by a minimum 2 coat paint
system with a minimum total dry film thickness of 250 microns
are considered a suitable protections.
---e-n-d--o-f---G-u-i-d-a-n-c-e---n-o-t-e--
105 SolderM connections are to be able to withstand a temperature of at least 425°C if refrigerants of Group 2 are used.
106 When tin soldering, the solder is to be of a type which does.
not decompose.
107 Cold refrigerant liquid and gas pipes and cold brine
pipes are to be insulated where necessary to prevent the
harmful or damaging effect on equipment, cargo chambers
or cargo from condensation or frosting (with subsequent
defrosting).
108 Any insulation of refrigerant and brine pipes is to be
efficiently protected against the diffusion of moisture.
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For sea water cooled R717 condensers the condenser tubes and
tubepl.ates are to be made of materials resistant to both sea water
and ammonia corrosion. Use of coating or lining systems will not
be accepted in lieu of corrosion resistant materials.
205 Heat exchangers including plate heat exchangers for the
refrigerant or for compressor lubricating oil are to be certified by
the Society except as .<lated in 206 and 207.
206 Direct expansion air coolers with an air cooling surface,
including extended surface, exceeding 50 m2 are to be certified
by the Society.
207 Direct expansion plate freezers need not be certified by the
Society provided use of acceptable materials and compliance with
102 can be documented.
D 300
Brine piping system and vessels
301 ,Special consideration is to be given to corrosion resistance of materials.
Guidance note:
A corrosion-feducing agent consisting of 2,0 kg sodium dichromate + 0,54 kg caustic soda for each m3 of the solution should
be added to calcium chloride. The pH value is to be about 8. It
is advised that a closed brine system be installed.
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302 If internally galvanized vessels or pipes are used with a
closed system, and if the brine attacks zink, the vessels are to be
vented to a safe place in open air. At the outlet, the pipes are to
be equipped with safety equipment against back flaming.
303 With an open system, the rooms where internally galvanized brine tanks are located are to be effectively ventilated, and
brine, which generates gases with flash point lower than 30°C,
is not to be used.
304 The thickness of the brine pipes from the bottom of
the threads is not to be less than 2,5 mm.
D 400
Safety valves and discharge system
401
The refrigerant circuit(s) are to be protected against excessive pressure by safety relief valves, rupture discs or equivalent
arrangements.
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 10 - Pt.5 Ch.10 Sec.3
402 If a shut-off valve is located between the pressure vessel
and the safety valve, it is to be sealed in open position, and is to
be closed only during repairs. A signboard stating this requirement is to be fitted.
403 Vessels with shut-off valves which contain liquid refrigerant are to be protected by a safety valve. For refrigerants of Group
1, a safety disc which is corrosion-resistant, may be substituted
for the safety valve.
404
The safety valve and safety disc are to be located above the
surface of the liquid. They are to open at a pressure not kss than
the design pressure and are to be fully effective at a pressure
which is maximum 10% higher.
405
The safety valve and safety disc are to have a minimum
capacity determined from the following formula:
FS0,8
G=-rF
(kg/s)
= 58000 if the vessel is placed in a room which contains
combustible materials.
S
r
= 12000 otherwise.
= the total surface of the vessel(s) protected, in m 2.
= the heat of evaporation of the refrigerant in J/kg at the
relieving condition.
The minimum flow area required may for R22, Rl34a and R717
be decided from the following formula:
GC
A= IOK(p+l)
C
K
p
T
M
IT
VM
(cm)
= 141 for R22.
= 142 for Rl34a
= 136,5 for R717.
= the contraction coef)1Cient of the safety valve or the safety
disc
= the design pressure (gauge) as given in A500.
= absolute temperature in °Kat the relieving condit.ion.
= the molecular weight of the refrigerant.
A pipe with outlet opening at a position which is not considered dangerous for the ship or the surroundings of the ship,
is to be led from the safety valve or the safety disc.
If led to the atmosphere the outlet opening is to be protected
against rain and snow and is to be )llted with a protection net
made of corrosion resistant material to prevent ingress of foreign
objects.
When R7I7 is used as refrigerant the outlet is to be at a safe location as high as possible on the ship e.g. top of funnel or top
of mast. The outlet is to be directed upwards.
407
The discharge piping system from the relief devices is to
have suf)1Cient capacity to ensure critical flow through the relief
devices. In lieu of correct calculations, the following simplif"zed
formulae may be used for R22, Rl34a and R717:
2
dR22 = 36,4
(E G)
V
2
dR134a = 35,1 V(E G)
dR717 = 51,2 V(E GJ2
= internal diameter in mm of the discharge pipe.
When using the above formulae for calculating the diameter of a
particular piece of pipe, the sum of the mass flows in kg/s of all
relief devices connected to this piece of pipe is to be used.
D 500
502 Filters or strainers are to be located in the liquid lines
upstream of the expansion valves and in the suction lines
upstream of the compressors.
503 Any driers necessitated by the refrigerant used are to
be located in the liquid lines downstream of the condensers.
504 The drying agent is to be replaceable during operation.
D 600 Temperature, pressure and level indication
601 The temperatures of the refrigerant on the suction and
discharge sides of compressors, of the cooling water upstream and downstream of the condensers, of the brine and
the refrigerated sea water (RSW) feed and return as well as
of the refrigerant from all coolers and freezers with direct
expansion, are to be indicated.
602 The pressure of the refrigerant in the suction lines,
intermediate stages and delivery lines of the compressors, in
the refrigerant circulation pumps' delivery lines, in the return lines from all direct expansion air coolers and freezers
and on the brine pumps' pressure side are to be indicated.
603
Level indication is to be provided on liquid receivers.
lt is to be possible to close the indicators so that the loss of large
quantities of the refrigerant may be prevented in event of breakage.
2
406
d
system is to be fitted with heating arrangements to boil out
any accumulating refrigerant.
Oil separators, filters and driers
604
In case of liquid-level indicators with glass tubes, a valve
which closes automatically for the refrigerant or oil in event of
breakage, is to be )llted.
E. Instrumentation and Automation
E 100
General
101 The Rules Pt.4 Ch.5 regarding documentation to be
submitted for approval, system design, component design
aod installation are to be complied with.
E 200
Automatic control
201 Where automatically operated expansion valves are
used, manually operated bypass valves are to be provided.
Alternatively, duplicated automatic valves can be accepted.
202 The automatic control systems are to keep the cooling
capacities within acceptable limits at all design operating
conditions.
E 300
Monitoring
301 The monitoring system is to cover machinery and
equipment necessary for the safety of the cargo cooling
machinery and to ensure a correct carriage temperature for
the cargo. The parameters to be monitored will depend
upon output and type of machinery as well as arrangement
of the plant. Other combinations of measuring points than
those listed below may be accepted when an equivalent degree of safety is achieved.
302
A refrigerant leakage detection system with alarm covering
all spaces with refrigerating machinery, the outlet piping from
safety relief devices and, in case of direct expansion, all refrigerllted chambers is to be instalkd.
501 Oil separators are to be located in the pressure pipe
ahead of the condenser, or ahead of the intercooler, if any.
Jn case a sampling system with sequential analyzing is used, each
sampling point shall be analyzed at intervals not exceeding I hour.
Sampling lines shall be monitored with regard to flow failure.
The plant is to be arranged and equipped to ensure that any
lubricating oil bypassing the oil separator is satisfactorily
returned to the oil system. Whenever relevant, the lub oil
The sensors I sampling suction points are to be located with due
regard to the relative density of the refrigerant in gas form as well
as to the ventilation flow.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.3 - Page 11
The acoustic and optical alarm signals are to be given at such locations that crew members attending to an aklrm will not be led
to entering a space possibly Filed with refrigerant.
When R717 is used leakage detectors covering compartments with
refrigerating machinery (including process vessels) are to give
audible alarm within the compartment.
When R717 is used refrigerant leakages in the refrigerating muchinery room are to be detected at 3 different levels:
35 PPM
initial detection of leakage.
500PPM
access immediately dangerous. Automatic shutdown of refrigerating compressors, refrigerant
circulation pumps etc.
de-energising of non-Ex protected electrical
equipment.
1000 PPM
When R717 systems, in accordance with B115 and B116, are accepted in other spaces than a separate refrigerating machinery
room these spaces are to be covered by a refrigerant leakage detection systems with alarm levels 35 and 500 PPM respectively.
Leakage detection of R717 at 500 PPM and 1000 PPM levels is to
be of continuous type.
303
Alarm is required for the following fault conditions:
- fresh air fans, failure
- circulating fans, failure
- brine/RSW temperature, high and low
- low level in the brine header tank.
- sea cooling water temperature outlet condensers, high.
304 All chambers shall be fitted with equipment able to
give alarm in case the chamber temperature as defined in
A301 deviates from from high/low set values selected by the
vessel's officers.
305 Automatic stop of compressor with alarm is required
for the following fault conditions:
-
suction pressure, low
discharge pressure, high
discharge temperature, high
lubrication oil pressure, low
low superheat temperature in the suction line or low
compressor discharge temperature
- liquid return from evaporators, (e.g. high level in suction
line liquid separator).
306 For vessels without a continuous watch attending to
the refrigeration plant the above listed alarm and stop functions are, except as given in 302, to be connected to the
engine room alarm system.
DE'f NORSKE VERITAS
Rules for Ships , January 1999
Page 12 - Pt.5 Ch.1 O Sec.4
SECTION 4
REFRIGERATED CHAMBERS. CONSTRUCTION, INSULATION AND INSTRUMENTATION
Contents
A. Arrangement and Design
A 100 General
A 200 RSW tanks
B. Insulation Construction
B 100
General
B
B
B
B
Insulation on sides, bulkheads and below deck
Insulation on tank top and 'tween decks
Insulated hatches and doors
Protection of cooling grids and refrigerant pipes. Pipe and
other penetrations
Lining and protection of insulation
200
300
400
500
B 600
C. Protection against Moisture
C 100 Design and workmanship
108 Access doors and -hatches shall either be operable from
both sides or be fitted with catches to prevent inadvertent closing.
109
at
D. Air Circulation System and Drainage, Air, Sounding and
Water Pipes
D 100
D 200
D 300
107 All chambers and air cooler rooms are to have access
doors, hatches and ladders arranged for easy access and escape.
Due account shall be taken to the possibilities to remove injured
personnel and the use of stretchers as well as to obstructions by
the cargo when the chambers are loaded.
Cooled/frozen cargo chambers with direct expansion air coolers
and with vertical access are if they are normally manned, such
l1.'i on .fishing vessels and on .fish factory ships, to be .fllted with
permanent hoisting arrangements for removal of
injured/unconscious crew members.
Air circulation system
Drainage
Air, sounding and water pipes
All chambers and air cooler rooms are each to be .frtted with
least one conveniently located aklrm call button.
A 200 RSW tanks
201 Requirement for the lining and insulation of RSW
tanks are given in Ch.6 Sec. I E300.
B. Insulation Construction
E. Equipment for Temperature Measurements. Gas Indication
Equipment
E 100
E 200
E 300
Equipment for temperature measurements
C0 2 indication equipment
Oxygene indication equipment
B 100
A. Arrangement and Design
A 100
General
101 Gaslight bulkheads of steel or equivalent material are
to be erected between the refrigerated chambers and the
other rooms of the ship, as well as between the individual
chambers, if these are intended to contain cargo which interacts with gas produced by the cargo in an adjacent
chamber.
Each separately insulated chamber or group of chambers
shall be gaslight.
Guidance note:
With all hatches, ports, doors, ventilation outlets and other
openings closed with their normal closing appliances, an air
supply through the ventilation inlet giving an internal overpressure in the chamber(s) of 40 mm water column should normally
not cause an air flow in excess of 0,25 air changes per hour.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
102 Where oil tanks are located adjacent to vertical boundaries of refrigerated chambers, no manholes in these
boundaries are permitted.
103 Bilge wells are to be separated from the insulated
cargo chambers by a gas tight construction.
104 All hatches, cargo ports, doors, etc., which lead to the
refrigerated chambers, as well as pipes and ducts leading
through the refrigerated chambers, are to be satisfactorily
gaslight.
105 Tank top insulation in way of manholes is to be provided with a liquid tight coaming to prevent seepage into the
insulation.
106
General
101 Steel, which is to be covered with insulation, is to be
cleaned thoroughly and is to be painted with a rust-proofmg
coating.
Uninsulated steam supply and return pipes are not to be
located within double bottom fuel oil tanks below insulated cargo
chambers. Such pipes are normally to be insulated and located
within a pipe duct or to be led above deck.
Guidance note:
Shot blasting to SA 2.5 followed by a minimum 2 coat paint
system with a minimum total dry film thickness of 250 microns
is considered a suitable protection.
---e-n-d--o-f---G-u-i-d-a-n-c-e---n-o-t-e---
102 Bolts, nails and steel fittings are to be galvanized.
103 Concealed woodwork is to be pressure/vacuum impregnated with a recognized odourless preservative. All
wooden materials are to be well dried before use.
104 Metallic fittings or other items passing through the
insulation and which may form a heat-conducting bridge, are
to be avoided as far as practicable.
105 On the 'tween decks and bulkheads which are not
fully insulated, strip insulation is to be used.
Guidance note:
If the insulation is made from slabs, several layers laid with
staggered ends, should preferably be used. The seams between
the slabs are to be filled with a recognized, odourless material.
The thickness of the insulation should preferably be adjusted so
that the heat transmission per unit area is of the same magnitude
for all surfaces.
Heat gain through the deck plates, bulkhead plates and stiffeners
should preferably not exceed 20 W per metre of edge length.
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106 Insulation adjacent to engine and boiler room is to be
made of non-combustible material.
107 The lining and insulation is to be arranged for regular
inspection of the insulation and hull members behind it.
B 200
Insulation on sides, bulkheads and below deck
201 The insulation is to be securely fastened or thoroughly
packed, so that settling caused by vibrations and deformations is avoided.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.4 - Page 13
Guidance note:
At frames and deck beruns, any form of heat-conducting bridge
should preferably be avoided.
Where plane bulkheads are insulated, attempts should be made
to reduce or eliminate through connections by using insulation
materials with sufficient strength to resist load from the cargo.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
B 300
Insulation on tank top and 'tween decks
Guidance note:
The insulation should preferably be of a material with sufficient
strength to withstand the weight from the cargo, so that through
connections are avoided.
The insulation, especially on the tank top, should preferably be
of a material with particularly high resistance to penetration of
moisture.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
B 400
Insulated hatches and doors
Guidance note:
Attempts should be made to reduce the weight of the hatches and
the doors to the extent possible, using light materials and constructions which have little tendency to warp. Insulation materials with great strength, little weight and a low coefficient of
thermal conductivity should preferably be chosen. Attempts
should be made to avoid heat-conducting bridges.
602 The lining of all surfaces is to have sufficient strength
to withstand load from the cargo.
603 In addition to sufficient meehanical strength, the lining
is to be:
- impervious to water, and it is llot to crack at the service
temperatures and stresses
- satisfactorily resistant to corrosion by oil, organic matter
or other material with which it may come into contact
- odourless. Bitumen solution is not to be used unless all
the solution agent is evaporated before the room is used.
604 Under the hatches and approximately 0,6 m outside
their edges, the insulation on the tank top and shaft tunnel
is to be protected with an extra covering of hardwood about
50 mm thick, or another efficient covering, for instanCe
fixed or removable gratings, which is not damaged to any
appreciable extent by impacts during loading and unloading.
605 Where the insulation is to support fork lift trucks, the
strength of the lining and its support is to be demonstrated.
A sample of the insulation construction, approximately 4 x
4 m, is to be prepared and tested by a fully loaded fork lift
truck being driven and manoeuvred over the sample.
C. Protection against Moisture
---e-ri.-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
401 Hatches and doors with frames, packings, hinges,
locking devices etc. are to be of reasonably gas tight construction.
402 On ships designed for carriage of fruit in general or
bananas, with class notation Reefer hatch covers and doors
between insulated chambers must be provided with double
seal packings. Hatch covers and doors exposed to weather,
must in addition to double seal packing have packing for
weathertightness with compression bar of corrosion resistant
material. For smaller covers or doors exposed to weather,
two packings may be accepted.
403 Fittings, hinges and handles are to be corrosion resistant.
B 500 Protection of cooling grids and refrigerant pipes.
Pipe and other penetrations
501 Cooling grids located on sides and bulkheads are to
be protected with dunnage ribs.
Guidance note:
Wooden ribs should preferably be about 50 x 150 mm with a
spacing of approxiriiately 300 mm.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
502 The refrigerant pipes are to be securely fastened and
protected.
503
Where the refrigerant pipes, electrical cables etc. pass
through gaslight bulkheads or decks, the construction is to be
gaslight and fr.reproof, Refrigerant pipes are not to be in me-
C 100
Design and workmanship
Guidance note:
When insulating, care should be taken that the air in the room
has a dew point lower than the temperature of the surfaces being
insulated.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
101 Air pipes, hatchways, etc. are to be constructed and
located such that the chambers are not fed with moisture
from spray and shipped water.
102 Before the insulation is laid, the tightness of bulkheads
is to be verified by hose or pressure testing.
Guidance note:
Insulation should preferably be laid on the side of the bulkhead
which is normally cooled.
---e-n-d---o-f---G-u-i-d-a -n-c-e---n-o-t-e---
103 Provisions are to be made for the efficient drainage
of the chambers, especially if the ship is to carry cargo giving off water.
104 The inside lining is to be constructed of a material
with high resistance to moisture and moisture diffusion. All
the joints, inclusive of the joint between the deck and sides,
are to be as resistant as possible to moisture diffusion.
Guidance note:
Measures against condensation on the warm side of the bulkheads and decks should preferably be taken by using heating
cables or similar devices.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
tallic contact with the steel parts of the ship. Stuffing boxes
are to be able to take thermal movements of the pipes.
B 600
Lining and protection of insulation
601 The lining in refrigerated chambers is to be constructed and fitted to prevent circulating air from entering
the insulation, causing forced convection in the insulation.
When using insulation materials with low resistance to convection, special care is to be taken. The lining on decks,
sides, bulkheads and below decks is to be of a material and
of a workmanship which will not be damaged or allow water
to penetrate into the insulation during hosing down of the
chambers.
D. Air Circulation System and Drainage, Air,
Sounding and Water Pipes
D 100
Air circulation system
101 The chambers are to be arranged for adequate air circulation around/through the cargo taking into account the
types of cargoes carried. The arrangements are to be satisfactory also when the chambers are only partially loaded.
The air circulation arrangements may be based on permanent installations, on portable equipment and/or on opera-
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 14 - Pt.5 Ch.10 Sec.4
tional procedures for stowage and packing of the cargo.
Local high-velocity air streams which may damage the cargo
are to be avoided. A permanently installed forced air circulation system is to be arranged with well-rounded comers
and other detail designs to reduce the air flow resistance.
304 Air, sounding and water pipes penetrating the tank top are
to have substantial wall thickness in way of the insulation on the
tank top.
102 In ships with class notation Reefer designed for carriage of fruit in general or bananas, the chambers are to be
fitted with an arrangement for distributing the cooling air at
the bottom, e.g. by means of ducts and· grating.
In ships with class notation Reefer designed for carriage of
fruit in general or bananas, 2 independent level alarms are
required in each bilge well without sounding pipe.
103 In ships not fitted with an air distribution grating the
cargo is to be stowed on pallets or otherwise be lifted clear
of the deck or bottom insulation to ensure air circulation
below the cargo.
104 Unless arrangements are made for air circulation
through the stowed cargo the bulkheads and ship sides are
to be fitted with battens.
105 In ships with class notation Reefer provision is to be
made for adequate air circulation in the chambers inside
hatch coamings foreseen for stowage of cargo, for instance
by return air channels from top of hatch coamings.
106 The walls of air ducts and air cooler rooms are to have
sufficient strength to resist pressure from the cargo, and are
to be as airtight as possible, especially against insulated
surfaces.
D 200
Drainage
201 Drain pipes from the chambers and from the cooler
drip trays are to have liquid-sealed traps or equivalent means
to prevent air communication between chambers and from
the bilge wells to the chambers.
202
Drain pipes from chambers and from cooler drip trays
are to have check valves or equivalent means to prevent
water communication between chambers.
203 Liquid-sealed traps are normally to be placed on the
warm side of the insulation and are to have at least the following pressure heads: 100 mm when connected to air
ducts, 50 mm otherwise.
204 If liquid-sealed traps are located inside the refrigerated
spaces, they are to be easily accessible for checking and refilling with brine.
205 Drain pipes from other rooms are not to lead down to
bilge wells for refrigerated chambers.
206
Guidance note:
Overboard drain pipes are to meet the requirements given in Pt.3
Ch.I Sec.11 Kand Pt.3 Ch.2 Sec.11 K.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
D 300
Air, sounding and water pipes
301 Air and sounding pipes through the cold chambers are
to be effectively insulated.
302 Pipes are to be well insulated from cold decks, but are
to have the greatest possible contact with relatively warm
decks, bulkheads or ship's sides.
303 The inside diameter of sounding pipes is not to be less
than 65 mm, if the temperature of the chamber is below
0°C. Sounding pipes for oil tanks are not to end in refrigerated chambers or rooms for fans or air coolers.
Guidance note:
Water pipes and air and sounding pipes through freezing chambers should preferably be avoided.
---e-n-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
305 Bilge wells for refrigeraied chambers will be accepted with
a level alarm in lieu of a sounding pipe.
E. Equipment for Temperature Measurements.
Gas Indication Equipment
E 100
Equipment for temperature measuremenis
101 The Rules Pt.4 Ch.5 regarding documentation to be
submitted for approval, system design, component design,
and installation are to be complied with.
102 In chambers with forced air circulation through coolers, at least one thermometer is required in the circulated air
entering each air cooler, and at least one in the circulated
air leaving each air cooler. Additional thermometers may
be required dependent upon the arrangement of the air circulation system.
103 In chambers without forced circulation through air
coolers the number of thermometers is not to be less than:
Up to approximately 200 m3 net volume
Up to approximately 400 m3 net volume
Up to approximately 600 m3 net volume
3 thermometers
4 thermometers
5 thermometers
and then one thermometer in addition for each approxi111ately 300 m 3 net volume. On ships intended exclusively
for frozen cargo a smaller number of thermometers may be
accepted based on the arrangement of the air coolers.
104 More thermometers may be required depending upon
the geometrical configuration of the chambers.
105 The thermometers are to be suitably arranged in the
refrigerated chambers and in such a way that temperature
reading is possible without entering the chamber.
106 For RSW installations thermometers are required in
pipes entering and leaving RSW tanks.
107 When only electronic thermometers are fitted, at least
two mutually independent systems with separate power supply are to be installed. The sensing elements in each
chamber are to be divided between the two systems in an
appropriate manner. One of the indicating instruments may
be a data logger. The data logger is to comply with the requirements in 108.
108 The thermometers are to cover the temperature range
from 10°C above the highest expected cargo temperature at
loading to 5 °C below the lowest design operating chamber
temperature.
109 The accuracy of the thermometers at the design temperatures is to be ±0,5°C for frozen cargo and ±0,25°C for
fruit in general and bananas.
In the above limits are included possible errors from resistance variations in cables and instrument reading errors. The
combined errors of instrument reading and hysteresis are to
be less than 0, 1°C.
The scale deflection of analog instruments is for bananas and
fruit in general not to be less than approximately 5 mm/° C
and for frozen cargo not to be less than 2,5 mm/°C.
The temperature reading is to be possible within 0, 1° C on
both analog instruments and digital displays.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.4 - Page 15
110 The sensing elements are to be well protected against
damage from mechanical abuse and moisture. They are to
be permanently connected to their instruments, i.e. no
plug-in connections are allowed.
E 200 C02 indication equipment
201 All chambers designed for carriage of fruit in general
or bananas are to be fitted with permanently installed
equipment for indication of C02 content.
111 Instruments for remote thermometers are to comply
with the requirements of Pt.4 Ch.5. The installation is in
general to comply with the requirements of Pt.4 Ch.4 Electrical Installations.
E 300 Oxygene indication equipment
301 Cargo chambers are to be f'llled with arrangements to facilitate measurement of the 0 2 content without entering the
chamber. Any portabk 0 2 analyzer necessary for this purpose is
to be kept onboard.
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 16 - Pt.5 Ch.1 O Sec.5
SECTION 5
CONTROLLED ATMOSPHERE
Contents
- the location of the portable unit onboard the ship is subject to approval
A. General
A 100 Application
A 200
A 300
A 400
- the scantlings of the portable unit are to be in accordance
with the requirements for a deckhouse in the same location. If the unit is built as a container with ISO type
corner fittings, relevant parts of the DNV Rules for
Freight Containers will be applied. The container fittings
for the portable unit are to meet the requirements of Ch. 2
Sec.6
Class notations
Basic assumptions
Documentation
B. Arrangement and System
B 100 General
B
B
B
B
200
300
400
500
Access
Piping systems
Ventilation of adjacent spaces
N2 release pre.alarm
-
the portable unit with its equipment is to be subject to
approval by the Society and is to be covered by a Certification Procedure accepting its use in connection with
one or more identified ships
-
each time a portable unit is placed onboard a ship, a
preloading functional test in accordance with an approved
procedure is required. Such tests need not be carried out
in the presence of a surveyor
C. Operational Performance
C 100
Atmosphere quality
C 200
Required capacities
D. Nitrogen Generator. Carbon Dioxide Scrubbers
D 100
D 200
Nitrogen generator
Carbon dioxide scrubbers
- the portable unit is to be covered by annual and complete
periodical surveys. Such surveys shall be carried out
while the unit is installed onboard one of the applicable
ships to facilitate realistic testing.
E. Electrical Installations
E 100 General
E 200
Cable penetrations
F. Instrumentation
F
F
F
F
100
200
300
400
A 300
General
Gas monitoring
Control of cargo chamber atmosphere
Alarm and monitoring
Basic assumptions
It has been assumed that in no cases, except for the
rescue of personnel in danger, will spaces with a low 0 2
content be entered.
301
G. Instruction Manual. Personnel Protection Equipment
G 100 Instruction manual
G 200 Personnel protection equipment
302 It has been assumed that appropriate onboard procedures will be established to ensure that all CA compartments
are free from personnel and adequately locked before injection of low 0 2 gas is commenced.
303
A. General
A 100
Application
101 The requirements in this Section apply to ships built
and equipped for operation with a controlled atmosphere
(CA) with low oxygen content in the refrigerated cargo
chambers for the purpose of slowing down the ripening
process and quality reduction of bananas and fruit in general.
102 These requirements are supplementary to those applicable for class notations Reefer or RM.
A 200
Class notations
201
Ships satisfying the requirements of this Section may
be given one of the following class notations:
Unless a thorough tightness test has been carried out
after the closing of the 'tween deck hatches, it has been assumed that a cargo chamber will not be put under controlled
atmosphere until loading of all chambers under the same
main weather deck hatch is completed. Correspondingly it
has been assumed that unloading of a chamber will not be
commenced until all chambers under the same main hatch
have been completely ventilated to a normal atmosphere
unless the above prescribed tightness test was carried out
prior to the loading of the upper chambers.
It has been assumed that when one or more chambers
are under controlled atmosphere then the gas monitoring and
alarm system of any adjacent chamber with a normal atmosphere will be kept in operation with relevant alarm set
point.
304
It has been assumed that the controlled atmosphere
chambers are maintained at a pressure as close as possible
to the atmospheric pressure.
305
CA; which applies to ships fully and permanently equipped
for operation with controlled atmosphere.
306
CA (port.); which applies to ships for which the use of a
portable nitrogen generating and possibly instrumentation
unit has been foreseen for operation with controlled atmosphere.
A 400
202 The following requirements apply in case of class notation CA (port.):
- the portable unit may be connnon to several ships
~
the complete installation including the portable unit is in
principle to comply with all relevant items of this Section.
It has been assumed that certified test gases will be
available onboard and used for regular calibration of all gas
analyzing equipment.
Documentation
AOl 1n addition to the documentation required for the class
notations Reefer or RM the following documentation is to
be submitted:
For approval:
- an arrangement plan including:
- location of CA chambers and gas tight subdivisions
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.1 O Sec.5 - Page 17
supply the pressure loss during 15 minutes is not to exceed 30%
of the design overpressure.
- design overpressure
- location of equipment for CA
-
105
arrangement and use of spaces adjacent to CA chambers
- piping diagram for CA supply and vent gas
- plan showing pipes led through CA chambers
- drawings of cleating, hinging and sealing arrangement for
gaslight weather- and 'tween deck main hatches, access
hatches and loading- and access doors
- gas tight glands for pipe and cable penetrations
- ventilation arrangement including:
- gasfreeing of CA chambers
-
ventilation of spaces adjacent to CA chambers or
containing CA equipment
-
plan showing the location of outlets from relief valves,
ventilation systems etc. of gases which may have abnormal low or high oxygen content
-
capacity calculations for CA chamber pressure relief
valves
- diagram of N2 release prealarrn system
-
plan of water seal arrangement for drains from CA
chambers
Each chamber or gaslight group of chambers is to be fitted
with at least one pressure relief valve. The pressure set point and
the pressure relieving capacity are to be_such that with the maximum capacity of the gas generating unit being delivered to any
one chamber, the pressure in that chamber is not to exceed its
design overpressure.
106 The liquid sealed traps on drains from chambers, air
cooler drip trays etc. are to have a liquid head at least 50 mm
greater than the chamber design overpressure. When the drains
are connected to the pressure side of the chamber air circukllion
fans, the excess liquid head of the traps is to be at least 100 mm
or otherwise as necessary due to the maximum pressure head of
the circulation fans.
107 Bilge wells for CA chambers are to be flttea with air pipes
to a safe location on open deck. Spaces and chambers not intended for CA are not to have bilge wells common with CA
chambers.
108 N2 generating equipment is not to be located within the
accommodation. Such equipment is preferably to be located within
a well ventilated part of the engine room. In case N 2 generating
equipment is located within a separate space, this space is to be
equipped with a permanent ventilation system of the extraction
type giving at least 6 air changes per hour.
109 An hazardous area arrangement plan including also general information about the hazards caused by a low oxygen level
is to be posted within the crews living quarters. The information
is to be given in a language/languages understood by the crew.
Guidance note:
- plans of nitrogen generating equipment
- plans of carbon dioxide scrubber equipment if installed
- electrical drawings; Reference is made to Pt.4 Ch.4 Sec. I
ClOO
When in this Section a reference is made to "spaces adjacent to
CA chambers" this does not include other cargo chambers
whether or not used or arranged for CA. Requirements for such
cargo chambers are given directly in the text.
---e-n-d--o-f---G-u-i-d-a-n-c-e--n-o-t-e---
- instruction manual
-
documentation relating to a possible portable equipment
unit including its installation onboard.
B 200 Access
201 All access doors and -hatches to CA chambers and air
cooler rooms are to be fitted with locks/pad lock arrangements.
Key for emergency opening is to be available in a nearby glass
locker. Signboards warning against the possibility of a low oxygen
atmosphere are to be fitted.
For information:
- description of the CA installation.
Information required above may be included in drawings and documentation submitted for class notations Reefer
or RM.
B 300 Piping systems
301 Pipes for other media are preferably not to be led through
403 For requirements for documentation of instrumentation and automation, including computer based control and
monitoring, see Sec .1.
302
402
B. Arrangement and System
B 100
101
General
For assignment of the class notations CA or CA
(port.) at least 50% of the ship's total refrigerated cargo
chamber volume is to meet the requirements for operation
with controlled atmosphere.
102 Chambers intended for CA are to be gaslight. Alternatively
a group of two or more chambers may be arranged as a common
gaslight unit intended to be operated with the same atmosphere.
103
A design overpressure with respect to gas tightness is to
be defined for the chambers. The design overpressure is to be
between 0,002 bar (20 mm water column) and 0,01 bar (100 mm
water column).
104 During a tightness test after compkted construction and
outfitting all chambers or gaslight groups of chambers are individually to be pressurized to their design overpressure. With all
openings closed with the ordinary closing devices and without air
chambers with controlled atmosphere.
All pipes (e.g. air pipes, sounding pipes, drain pipes from
overlaying chambers, ventilation pipes for underlaying chambers,
etc.) led through chambers with controlled atmosphere and which
in case of a kakage may cause unintended low oxygen atmosphere
in other spaces, are to be of a material and of a design that will
ensure permanent tightness. Such pipes are to, if covered by the
chamber insulation and if made of black steel, have wall thicknesses in accordance with the right hand coloumn ~f Table A2
of Pt.4 Ch.I Sec.6 A200. Gas sampling pipes will be considered
specially.
Guidance note:
When acceptable with regard to watertight and fire protecting
subdivision it is adviced to utilize plastic pipes as far as possible.
Spiro type ventilation ducts will be accepted only within the
chamber where they have their open ends.
---e-n-d---o-f---G-u-i-d-a-n-c-e--n-o-t-e---
303
N2 supply pipes are not to pass through the accommodation and are otherwise to be located with due regard to the hazards of a possible pipe leakage.
304
In case the system is arranged for external supply of N'lJ
an automatic shut off valve is to be fitted at the connection for the
external supply. This valve is to close in case of excessive pressure
in any of the CA chambers. Alternative means to protect the
chambers against an excessive supply of N1 wlll be specially considered.
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 18 - Pt.5 Ch.10 Sec.5
305
The Nz inlet valve arrangement to each chamber or gaslight group of chambers is to include a set of valves in an interlocked fail to safe double-block-and-bleed arrangement. To
facilitate operation without an overpressure in the CA
chambers, it is recommended that each. chamber or gaslight
group of chambers is fitted with a vent valve connected to
the inlet valve arrangement to ensure that supply of Nz is
normally carried out with the chamber vent valve in open
position. An override arrangement with automatic reset to
the normal condition may be arranged.
Arrangements for serial supply of N2 between chambers will be
specially considered.
When a portable gas generating unit with separate hose connections to each CA chamber or gastight group of chambers is
used, the double-block-and-bleed arrangement may be ommitted
provided operational procedures are established to ensure that the
hoses are not connected until the chamber is ready to be put under
controlled atmosphere and to ensure that hoses are not connected
for other CA chambers. Similarly the procedures are to ensure
that hoses are disconnected prior to unloading the chamber.
306
All outlets from CA chambers and from pressure relief
valves on the Nz distribution pipes are to be located at least 2 m
above the main deck or any gangway, platform, trunk, etc., if situated within 4 m of the gangway, p"/atform, trunk, etc. Due regard is to be given to the distance between such outlets and
venti"/ation intakes or openings to spaces.
307
Outlets used during ventilation of the CA chambers are to
be directed vertically upwards. See C202.
308
Pipes connected to CA chambers are normally not to have
open ends or connection possibilities within enclosed spaces.
Equipment connected to such pipes may normally be located
within enclosed spaces only if the equipment is substantially gaslight.
B 400
Ventilation of adjacent spaces
401 All normally accessible spaces adjacent to cargo chambers
with controlled atmosphere or where a pipe leakage, equipment
leakage etc. may cause an oxygen deficient atmosphere, are to
have a permanent venti"/ation system operable from outside the
space and giving at least 6 air changes pr. hour.
Guidance note:
Spaces without permanent electrical lighting will normally not
be required to have a fixed ventilation system.
---e-ri-d---o-f---G-u-i-d-a-n-c-e---n-o-t-e---
402 All other spaces or tanks adjacent to cargo chambers with
controlled atmosphere are to be arranged for efficient ventilation,
e.g. by use of portable ventilators. Suitable air inlet and exhaust
openings are to be arranged. Permanent ducting within the space
or tank may be required if considered necessary. For ballast tanks,
baTlosting with subsequent deballasting will be considered as efficient ventilation.
403 At least two portable ventilators suitable for use on the
above mentioned inlet or exhaust openings and with a nominal
capacity equivalent to at least 2 air changes pr. hour in the "largest
of the relevant spaces/tanks are to be available onboard.
lyzer in such a way that akzrm is not given when the 0 2 content
in the chamber is below 14% by volume. ,
C. Operational Performance
C 100 Atmosphere quality
101 Equipment is to be installed making it possible to
maintain in any chamber or gaslight group of chambers any
Oz level between 10,0% and 2,0% by volume with an accuracy of ±0,2 % by volume or better.
102 The ship is to be fitted with equipment making it
possible to reduce excessive concentrations of COi in any
chamber or gaslight group of chambers. Between 0,2 % and
10,0% COz by volume the equipment is to make it possible
to maintain any desired C02 concentration with an accuracy
of ±0,2 % by volume or better.
C 200 Required capacities
201 The Nz generating equipment at normal operating
temperature and at 4,0% Oz is to have a capacity in Nm3/h
not less than 0,05 times the total bale volume of all CA
chambers. At 2,0% Oz the capacity is to be at least 50% of
the above. The capacities stated are to be available at the
inlet openings to the chambers at a backpressure equal to the
pressure setting of the pressure relief valves.
202 Each chamber or gaslight group of chambers is to be fitted
with a ventilation system able to give at least 2 air changes pr.
hour based on the bale volumes. See Sec.3 8213.
D. Nitrogen Generator. Carbon Dioxide Scrubbers
D 100 Nitrogen generator
101 The piping system, the pressure vessels including separation or adsorbtion units and the compressors are to meet the
requirements of Pt.4.
102 Active components including compressors are to be
arranged with redundancy. Two compressors with approximately 50 % of the required capacity will be accepted. The
main and additional units need not be exclusive for the nitrogen generator provided they may always be made available for this purpose. Passive components such as gas
separators or adsorbtion units need not be duplicated.
103 A suitable separator/filter system to ensure that the
delivered gas is sufficiently clean for use in the cargo
chambers, and to prevent damages to any gas separating or
adsorbtion equipment, is to be installed.
104 Compressor air intakes are to be located to ensure that
contaminated air is not drawn into the compressors.
105 Exhaust of Oz enriched gases is to be to safe locations on
open deck.
B 500 Nz release prealarm
501 Means is to be provided for automatically giving audible
warning of injection of Nz into any chamber or gaslight group
of chambers. The alarm is to be given continuously for at least
60 seconds before injection can take pkzce. The operating medium
for the alarm is to be taken from the supply of operating medium
for the double-block-and-bleed inlet valve arrangement in such a
way that the inlet valve cannot be opened unless the akzrm signal
has been given. The alarm may be interlocked with the Oz ana-
106 Exhaust of Nz enriched gases is to be to safe locations on
open deck. See 8306.
107 Any Nz storage vessel is to be jilted with non-retarn valves
on the inlet connections.
108 The Nz delivery line shall be jilted with a safety relief valve
s;zed for the maximum delivery of the nitrogen generating equipment.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch. 10 Sec.5 - Page 19
D 200 Carbon dioxide scrubbers
201 C02 scrubbers for atmosphere control, if fllled, will be
specially considered.
E. Electrical Installations
E 100 General
101 Reference is made to Pt.4 Ch.4 concerning general requirements for electrical installations.
In addition, refer to Sec.3 C.
E 200 Cable penetrations
201
Cable penetrations between cargo chambers and surrounding spaces, and between individual cargo chambers are to
be arranged gas tight. The penetrations may be arranged wiJh
separate glands for each cable, or wiJh boxes or glands filled wiJh
a suitable packing or molded material.
F. Instrumentation
206
Common sampling lines for the measurement of Oz, C02
and refrigerant gas may be arranged. "
207 Oz and COz analyzers are to have an accuracy of at least
±0,1% by volume or better. The oxygen analyzer(s) are to have
a range of 0 to 21% 0 2. The COz anqlyzer(s) are to have a range
of at least 0 lo 15% C02.
208
Closeable penetrations into each chamber or space referred
to in 201 and 203 and not utilizing any sampling lines for fu:ed
gas analyzers required by 201 to 207, are to be installed in order
to facilitate measurements of the quality of the atmosphere wiJh
portable gas analyzers in case the fu:ed equipment/ordinary sampling lines are out of order. At least two portable gas analyzers
for Oz and at least one portable gas analyzer for C02 are to be
kept onboard.
209
All.spaces adjacent to CA chambers and not arranged for
normal access by personnel are to be arranged for use of the
portable 0 2 analyzers required in 208.
F 300
F 400
F 100 General
101 For instrumentation and automation, including computer
based control and monitoring, the requirements in this chapter
are additional to those given in Pt.4 Ch.5.
102 Indication, monitoring, logging and/or control of atmosphere quality in cargo area as well as of other functions
required by this Section are to be arranged at a centralized
control stand.
103
Control of cargo chamber atmosphere
Injection of niJrogen and removal of C02 may be arranged
either manually or automatically in order to control chamber atmosphere. If automatic control 'is arranged, separate gas ana'/yzing equipment is to be installed for this purpose.
301
Alarm and monitoring
401
An aklrm system for monitoring of atmosphere in cargo
area and other functions is to be installed according to Table Fl.
This aklrm system may be integral with the ship's main aklrm and
monitoring system, but a proper grouping is to be arranged in
order to separate from other types of aklrm i.e. machinery aklrms.
This also covers extension aklrms, which shall not disturb personnel without cargo responsibilities.
Table Fl Alarm points
Item
0 7 content, high
For cable penetrations, see E200.
F 200 Gas monitoring
201 For CA chambers equipment for measurement of 0 2 and
C02 contents in cargo chamber atmosphere is to be installed. At
least one measuring point each for 0 2 and C02 is to be arranged
in any chamber which may be isoklted from other chambers.
202 Equipment for logging of above parameters automatically during the entire length of the loaded voyage is to be
installed. Gas monitors may be common with monitors for
indication and alarm.
203
All normally accessible spaces, including cargo chambers
not arranged for CA, which in case of leakage of bulkheads,
doors, hatches, pipes, etc. may be filled with an atmosphere with
reduced 0 2 concentration, are to are to be jiJted with equipment
for measurement of o2 content in the atmosphere. At least one
measuring point is to be installed in each space. The sampling
point is to be located with due regard to the ventilation arrangement for the space.
204
Discrete gas sensors may be installed locally at the respective points where measurement is to be taken, or a sampling
system may be arranged, with sampling pipes led from points of
measurement to a centralized gas monitor. One gas monitor each
for 0 2 and COz is required.
205
When a sampling system with sequential analyzing is arranged, each sampling point is to be analyzed at intervals not exceeding 1 hour. Sampling time at each point is to be at least equal
to 3 times pipe length divided by mean gas velocity in the connected
sampling line, in order to ensure that a fresh gas sample is analyzed. A/Jernatively gas may be drawn continuously through all
sampling lines.
Flow failure in the sampling lines is to be maniJored. The sampling system is to be designed to function at any chamber pressure
wiJhin pressure set points of pressure relief valves. The sampling
lines are to be arranged for easy testing of tightness.
Alarm
0 2 content, low
Oz content less than 21 %
co? content,
high
x
x
x
x
Atm. pressure, high
x
Liquid seal, low level
Ventilation failure
x
x
Compressor failure
x
Sampling lines, flow failure
Gas sensors, failure
Logger out of order
x
x
x
Comments
F..ach CA chamber/group
Each CA
chamber/group
Each space referred to
in 203
Each CA chamber/group
Each chamber/group if
external supply of
Automatic closing o
supply valve
Each liquid seal trap
Electric failure, each
fan required by Sec. 5
Electric failure, all compressers for N 2 generating equipment
All sampling lines
Out of normal range
':j·
G. Instruction Manual. Personnel Protection
Equipment
G 100 Instrnction manual
101
An instruction manual giving comprehensive information
about the following is to be available onboard:
- principal information about use of CA
- complete description of the ship's CA installation
- hazards caused by low oxygen atmospheres and consequential
effects on human beings
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 20 - Pt.5 Ch.10 Sec.5
- medical countermeasures in case of exposure to low oxygen
atmosphere
-
procedure for functional testing each time a portable gas
separating/instrumentation unit is placed onboard. See A202
-
operation, maintenance and calibration instructions for all
types of gas detectors onboard
- instructions regarding use of portable 0 2 analyzers with alarm
for personal protection
-
prohibition of entry of spaces under CA even with use of
breathing apparatus
- instructions with regard to loading of all chambers under the
- procedures relating to connection and disconnection of hoses
for N 2 when the double-block-and-bleed arrangement has been
omittell in connection with a portable gas generating unit
- procedures for checking that all gas 4e1ectors are in operation
and with correct a"/arm set points prior to injection of nitrogen
- gas freeing procedures for CA chambers ·
- procedures for checking completed gas freeing prior to entry
of CA chambers
- instructions with regard to gasfreeing of all chambers under
the same main hatch prior to entry
- instructions with regard to gasfreeing and atmosphere testing
of spaces without fu:ed ventilation and fu:ed gas detection
equipment.
same main hatch being compkted prior to injection of nitrogen
- procedures for checking chambers and locking door/hatches
prior to injection of nitrogen. Procedures for safe keeping of
key by responsible officer
- a list of signboards jiJted on all entrances to gas dangerous
spaces including those signboards which are to be checked
prior to a CA condition.
G 200
201
Personnel protection equipment
At least 10 off portable 0 2 ana!Jzers with alarm and of a
type designed to be continuously worn }Or personal protection are
required to be available onboard.
202
At least one set of oxygen resuscitation equipment is to be
available onb.oard.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.6 - Page 21
SECTION 6
TESTS
Contents
202 The brine and RSW side of all machinery and equipment is to be hydraulically pressure tested at 1,5 times the
working pressure, but not less than 5 bar. Open brine tanks
and other tanks not under pressure in service, are to be examined for tightness.
A. Pressure Tests of Components
A 100
A 200
General
Test pressures
B. Pressure Tests after Assembly
B 100
B 200
B 300
General
Pressure tests after erection on board
Drying of the refrigerating plant
B. Pressure Tests after Assembly
C. Function and Capacity Testing of the Completed Installation
B 100
C
C
C
C
C
C
C
101 The high-pressure side of the plant is to be tested pneumatically at a pressure of I x HP.
100
200
300
400
500
600
700
General
Refrigerating machinery, operational test
Thermometers. Gas indicating equipment
Air circulation and air renewal systems
Chamber tightness test
Insulation and heat balance test
Verification of refrigerating capacity
102 The low-pressure side of the plant is to be tested pneumatically at a pressure of Ix LP.
103 Compkted sub-assemblies («package• units) may be tightness-tested before fitting on board.
D. Testing of CA installations
D 100
D 200
104 Brine and RSW pipes are to be tested pneumatically
at twice the working pressure of the pump, but not less than
5 bar.
General
Instrumentation
B 200
A. Pressure Tests of Components
A 100
Pressure tests after erection on board
201 Pressure piping welded in place on board is to be subjected
to a strength test at 1,3 times the design pressure. If pneumatic,
this test may be a combined strength and tightness test.
General
101
A hydraulic strength test and a pneumatic tightness test are
to be carried out in the presence of the surveyor.
102 Hydraulic pressure tests may be carried out with any llquid,
including water, unkss it has an unfavourabk effect on the refrigerant. Pneumatic pressure tests may be carried out with nitrogen, C02 or air.
103 The strength and tightness tests may after special consid-
eration be combined into a single test.
202 The test required in 201 may be substituted by a pneumatic
tightness test at 1,0 times the design pressure, provided all pipes
and frttings with welded and soldered joints have previously been
subjected to a hydraulic strength test at 1,5 times the design pressure.
B 300
Drying of the refrigerating plant
301
Guidance note:
104
The test pressure is to be as stipulated in Tabk Al, where
HP and LP indicate design pressure on the high-pressure and
low-pressure sides, respectively, as given in Sec.3 ASOO.
Table Al Test pressures
Component
General
Hydraulic
High-pressure side of the compressors
such as cylinders, cylinder heads, shu- l,Sx HP
toff valves, and pipes
Low-pressure side of the compressors
1,5 x LP
such as crankcase, pipes and valves
High-pressure pressure vessels such as
condensers, liquid receivers, oil separa- 1,3 x HP
tors, plate heat exchangers etc.
Low-pressure pressure vessels such as
llquid separators for systems with pump
circulation of the refrigerant, RSW
coolers, brine coolers, etc. and other
1,3 x LP
low pressure heat exchangers including
air coolers, plate freezers and plate heat
exchangers
Pneumatic
After tightness testing and before charging with refrigerant it has
been assumed that an extensive drying out (vacuumation) of the
complete plant is carried out by the contractor. It is adviced that
pressure rise curves are recorded and analyzed to to verify
tightness and that the plant is dry. A satisfactory drying cannot
be carried out at very low temperatures.
---e-n-d---o-f---G-u-i-d-a-n-c-e--n-o-t-e--
Ix HP
Ix.LP
I xHP
C. Function and Capacity Testing of the Completed Installation
C 100
General
101 All systems, components and equipment are to be included in operational and capacity testing covering all design
functions and all design operating conditions.
Ix LP
102 Special considerations are to be given when testing
under low ambient temperatures. In such cases, heating of
the chambers may be demanded.
103 A complete narrative test report with with all recorded
and calculated data is to be given to the surveyor.
A 200
Test pressures
201 The cooling water side of all machinery and equipment is to be hydraulically pressure tested at 1,5 times the
working pressure of the cooling water pump, but not less
than 5 bar.
C 200
Refrigerating machinery, operational test
201 All components of the refrigerating machinery are to
be tested in operation. If deemed necessary, capacity tests
of the components may be demanded.
DET NORSKE VERITAS
Rules for Ships , January 1999
Page 22 - Pt.5 Ch.10 Sec.6
202 The testing is to be carried out in accordance with an
approved test program. The makers' adjustments and commissioning of the plant are to have been fully completed
prior to the testing. The plant in its entirety is to perform
satisfactorily and without hunting, instabilities or disruptions
during the complete test program. Normal maintenance
work including filter replacements or -cleaning may be carried out during convenient periods of the testing.
203 The test program is to include cooling down procedures from ambient temperature to all design operating
chamber (delivery air) temperatures with subsequent stable
delivery air temperatures for periods of at least 2 hours.
204 The test program is to be worked out to ensure that
all components and functions are tested including e.g.:
-
compressor capacity control system
- defrosting
operation with 2 or more different chamber temperatures
simultaneously.
During the operational test the plant is to be operated
in accordance with the operation manual as during normal
operations.
206 During the cooling down- and stable periods relevant
data is to be recorded at sufficiently short intervals to give
relevant information of the ongoing process. The intervals
is normally not to exceed 30 minutes during transient proc-
esses and 60 minutes during stable (stabilizing) periodes.
207 RSW tanks are to be cooled down to the tank design
temperature.
208
Tunnel freezers and plate freezers are to be tested by
simulated operation.
C 600
601 A thermographic investigation with infrared detecting
equipment is to be carried out to verify the completeness of
the insulation of the cargo chambers. For a series of two
or more identical sisterships the thermographic inves.tigation
602 The overall heat transfer coefficient of the insulation
and sufficient overall refrigerating capacity is to be verified
based on measurements taken during a heat balance test. All
chambers are to be cooled down to approximately their
lowest design operating temperature and normally at least
20°C below the mean ambient temperature. If the lowest
design operating temperature is different between the chambers, this difference is as far as possible to be maintained
during the heat balance test.
The chambers may be cooled down to the expected balance
temperature as found practicable. When the expected balance temperature has been reached, the plant shall be run
manually and as far as possible in accordance with the fol-
lowing:
-
the ingoing sea cooling water temperature may be autosign range
-
ments and all sensors for alarm and automatic stop functions
210
Safety instrumentation, including automatic stop functions, refrigerant leakage detection systems, emergency stops,
alarm call buttons etc. are to be tested on all vessels irrespectively
of class notations.
Thermometers. Gas indicating equipment
All chamber, cooling air, freezing tunnel and RSW
thermometers are to be tested for accuracy.
the compressor(s) are to be run with constant and well
defined capacity. Only one of several identical compressors need be in operation
are to be tested.
301
Insulation and heat balance test
matically controlled to a chosen set point within the de-
209 Instrumentation and automation systems are to be
tested. All alarm and automatic stop functions are to be
tested. The accuracy and set point of all indicating instru-
C 300
Chamber tightness test
external cold spot inspection with regard to excessive condensation or frost deposits while the chambers are at their
lowest design temperature.
- oil return
- oil transfer between units
205
C 500
501 On ships designed for carriage of bananas O< fruit in
general the tightness of the chambers (group of chambers)
is to be verified and the leakage rate is to be measured and
recorded.
may on the 2nd and the following ships be replaced by an
- refrigerant distribution between units
-
include measurements of air flow, electrical frequency or
rotational speed and power consumption. The resulting air
renewal rates are to be calculated and recorded.
-
each compressor shall be in operation together with the
other components of the same unit. See Sec.3 A201
-
automatic brine temperature controllers and chamber
temperature controllers are not to be in operation.
The situation may be accepted as in balance when:
-
302 Equipment for measuring the C02 concentration in the
chambers are to be tested.
the mean chamber temperature (measured by use of all
installed chamber temperature sensors) for each individual chamber and for all chambers together for each hour
of a 4 hour period have been changing less than
o,os c/h
0
C 400
Air circulation and air renewal systems
-
the ambient weather conditions have remained stable for
401 All fans for air coolers are to be tested. Dual or multi
speed fans are to be operationally tested at all speeds and
with applicable chamber temperature. Capacity testing is
required only at full speed. Variable speed fans need only
be tested at maximum speed and at the warmest chamber
- there are no indications of an unstable or off-balance situation.
design temperature. The testing is to include measurements
of the air flow, pressure difference across the fans, electrical
have chamber balance temperatures preferably within a
frequency or rotational speed and power consumption. The
resulting air circulation rates are to be calculated and recorded.
402 The air distribution within the chambers is to be
checked.
403 All air renewal fans are to be tested. Dual or multi
speed fans are to be tested operationally at all speeds. Capacity testing is required only at full speed. The testing is to
6 hours
Chambers with the same design operating temperature shall
range of l,5°C.
All data necessary for the verification calculations, see 700,
shall be recorded hourly covering a period of at least 6 hours
prior to the balance.
All heat input to the chambers (fan motors, lighting fixtures,
heat tracing on drainpipes, etc.) is to be measured by a calibrated kW-meter. Use of A-meter with estimate of coscf>
will not be accepted.
DET NORSKE VERITAS
Rules for Ships , January 1999
Pt.5 Ch.10 Sec.6 - Page 23
603
A heat balance test is to be carried out for RSW tanks.
C 700 Verification of refrigerating capacity
701 For all design operating conditions calculations are to
be made to verify that the installation has sufficient refrigerating capacity. The refrigerating capacity may be taken
from the compressor curves/data corrected as relevant. The
heat transfer losses are to be based on the heat transfer coefficient calculated after the balance test. In case of different
heat transfer coefficients for various areas, the overall coefficient are to be the same as the overall coefficient calculated
after the balance test. Evaporating and condensing temperatures are to be estimated based on observations during the
balance test and to be corrected in accordance with Sec.3
B201 and B404.
105 Nitrogen generating equipment is to be tested with
regard to capacity and quality of the delivered gas.
106
C02 scrubbers, if installed, ate to be tested.
D 200
Instrumentation
201
Upon completion of the installation, all functions are to
be tested according to an approved test program. With regard to
which of the testing requirements that are safety requirements
applicable to all ships with CA installation, reference is made to
the relevant "installation requirement.
'
202 Gas detectors are to be tested for zero, span and linearity
by means of certifwd test gas. In order to achieve this, three points
are to be tested, preferably 0%, 50% and 100% of range.
203
Flow failure alarms for gas sampling lines are to be tested
by blocking the relevant pipe manually. Gas sampling pipes are to
be tested for tightness.
D. Testing of CA installations
D 100
104 N 2 release prea/ann and inlet valve interlock arrangement
are to be tested.
"
General
Each chamber or gaslight group of chambers is to be individually pressure tested with air to the design overpressure to
verify that the leakage rate does not exceed that specifwd in Sec.5
BI04.
204 Alarm setpoints are preferably to be tested by letting
the measured parameter pass the setpoint value (may be
done by means of process parameter calibrators). Where this
is not possible, change of setpoint may be accepted for analog channels.
102
The nitrogen distribution system is to be hydraulically
pressure tested to at least 1,5 times the relief valve setting hut not
less than 5 bar.
205 Automatic control functions may be tested by introducing setpoint changes and observing stable adaption to
new value.
101
103 All other pipes/piping systems which in case of leakage
may cause gas with low oxygen content to flow into cargo chambers or other enclosed spaces are to be tightness tested to at least
2 bar or by equivalent means confumed to be tight.
206 Operator interface (display /indicating) panels are to
be checked for acceptable functionality and compliance with
Pt.4 Ch.5.
DET NORSKE VERITAS